diff --git a/src/main/java/de/ids_mannheim/korap/query/serialize/QuerySerializer.java b/src/main/java/de/ids_mannheim/korap/query/serialize/QuerySerializer.java
index a4a978b..ff11926 100644
--- a/src/main/java/de/ids_mannheim/korap/query/serialize/QuerySerializer.java
+++ b/src/main/java/de/ids_mannheim/korap/query/serialize/QuerySerializer.java
@@ -1,8 +1,6 @@
 package de.ids_mannheim.korap.query.serialize;
 
-import com.fasterxml.jackson.core.JsonGenerationException;
 import com.fasterxml.jackson.core.JsonProcessingException;
-import com.fasterxml.jackson.databind.JsonMappingException;
 import com.fasterxml.jackson.databind.ObjectMapper;
 import de.ids_mannheim.korap.query.serialize.util.KoralObjectGenerator;
 import de.ids_mannheim.korap.query.serialize.util.StatusCodes;
@@ -40,7 +38,7 @@
     public static String queryLanguageVersion;
 
     private AbstractQueryProcessor ast;
-    private Map<String, Object> collection = new LinkedHashMap<String, Object>();
+    private Map<String, Object> collection = new LinkedHashMap<>();
     private Map<String, Object> meta;
     private List<Object> errors;
     private List<Object> warnings;
@@ -82,10 +80,6 @@
             }catch (NullPointerException npe) {
                 npe.printStackTrace();
                 System.out.println("null\n");
-            }catch (JsonGenerationException e) {
-                e.printStackTrace();
-            }catch (JsonMappingException e) {
-                e.printStackTrace();
             }catch (IOException e) {
                 e.printStackTrace();
             }
@@ -180,20 +174,21 @@
             List warnings = (List) requestMap.get("warnings");
             List messages = (List) requestMap.get("messages");
             this.collection = mergeCollection(collection, this.collection);
-            requestMap.put("collection", this.collection);
+            if (this.collection != null && !this.collection.isEmpty())
+                requestMap.put("collection", this.collection);
             if (this.meta != null) {
                 meta.putAll(this.meta);
                 requestMap.put("meta", meta);
             }
-            if (this.errors != null) {
+            if (this.errors != null && !this.errors.isEmpty()) {
                 errors.addAll(this.errors);
                 requestMap.put("errors", errors);
             }
-            if (this.warnings != null) {
+            if (this.warnings != null && !this.warnings.isEmpty()) {
                 warnings.addAll(this.warnings);
                 requestMap.put("warnings", warnings);
             }
-            if (this.messages != null) {
+            if (this.messages != null && !this.messages.isEmpty()) {
                 messages.addAll(this.messages);
                 requestMap.put("messages", messages);
             }
@@ -205,15 +200,15 @@
 
     private Map<String, Object> mergeCollection(Map<String, Object> collection1,
             Map<String, Object> collection2) {
-        LinkedHashMap<String, Object> docGroup = KoralObjectGenerator
-                .makeDocGroup("and");
-        ArrayList<Object> operands = (ArrayList<Object>) docGroup
-                .get("operands");
         if (collection1 == null || collection1.isEmpty()) {
             return collection2;
         }else if (collection2 == null || collection2.isEmpty()) {
             return collection1;
         }else {
+            LinkedHashMap<String, Object> docGroup = KoralObjectGenerator
+                    .makeDocGroup("and");
+            ArrayList<Object> operands = (ArrayList<Object>) docGroup
+                    .get("operands");
             operands.add(collection1);
             operands.add(collection2);
             return docGroup;
@@ -243,14 +238,16 @@
 
     public QuerySerializer setCollection(String collection) {
         CollectionQueryProcessor tree = new CollectionQueryProcessor();
-        Map<String, Object> collectionRequest = tree.getRequestMap();
         tree.process(collection);
+        Map<String, Object> collectionRequest = tree.getRequestMap();
         if (collectionRequest.get("errors") != null)
             this.errors.addAll((List) collectionRequest.get("errors"));
         if (collectionRequest.get("warnings") != null)
             this.warnings.addAll((List) collectionRequest.get("warnings"));
         if (collectionRequest.get("messages") != null)
             this.messages.addAll((List) collectionRequest.get("messages"));
+        this.collection = (Map<String, Object>) collectionRequest
+                .get("collection");
         return this;
     }
 }
diff --git a/src/test/java/de/ids_mannheim/korap/query/serialize/CollectionQueryProcessorTest.java b/src/test/java/de/ids_mannheim/korap/query/serialize/CollectionQueryProcessorTest.java
index 62e6d1f..d7d3cf7 100644
--- a/src/test/java/de/ids_mannheim/korap/query/serialize/CollectionQueryProcessorTest.java
+++ b/src/test/java/de/ids_mannheim/korap/query/serialize/CollectionQueryProcessorTest.java
@@ -1,17 +1,15 @@
 package de.ids_mannheim.korap.query.serialize;
 
-import static org.junit.Assert.*;
+import com.fasterxml.jackson.core.JsonProcessingException;
+import com.fasterxml.jackson.databind.JsonNode;
+import com.fasterxml.jackson.databind.ObjectMapper;
+import org.junit.Test;
 
 import java.io.IOException;
 import java.util.ArrayList;
 
-import de.ids_mannheim.korap.query.serialize.QuerySerializer;
-
-import org.junit.Test;
-
-import com.fasterxml.jackson.core.JsonProcessingException;
-import com.fasterxml.jackson.databind.JsonNode;
-import com.fasterxml.jackson.databind.ObjectMapper;
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertTrue;
 
 public class CollectionQueryProcessorTest {
 
@@ -24,9 +22,8 @@
     ObjectMapper mapper = new ObjectMapper();
     JsonNode res;
 
-
     @Test
-    public void testContext () throws JsonProcessingException, IOException {
+    public void testContext() throws JsonProcessingException, IOException {
         collection = "textClass=politik";
         String contextString = "http://korap.ids-mannheim.de/ns/koral/0.3/context.jsonld";
         qs.setQuery(query, ql);
@@ -35,9 +32,8 @@
         assertEquals(contextString, res.get("@context").asText());
     }
 
-
     @Test
-    public void testSimple () throws JsonProcessingException, IOException {
+    public void testSimple() throws JsonProcessingException, IOException {
         collection = "textClass=politik";
         qs.setQuery(query, ql);
         qs.setCollection(collection);
@@ -57,9 +53,8 @@
         assertEquals("match:ne", res.at("/collection/match").asText());
     }
 
-
     @Test
-    public void testContains () throws JsonProcessingException, IOException {
+    public void testContains() throws JsonProcessingException, IOException {
         collection = "title~Mannheim";
         qs.setQuery(query, ql);
         qs.setCollection(collection);
@@ -79,29 +74,29 @@
         assertEquals("match:contains", res.at("/collection/match").asText());
     }
 
-
     @Test
-    public void testTwoConjuncts () throws JsonProcessingException, IOException {
+    public void testTwoConjuncts() throws JsonProcessingException, IOException {
         collection = "textClass=Sport & pubDate in 2014";
         qs.setQuery(query, ql);
         qs.setCollection(collection);
         res = mapper.readTree(qs.toJSON());
         assertEquals("koral:docGroup", res.at("/collection/@type").asText());
         assertEquals("operation:and", res.at("/collection/operation").asText());
-        assertEquals("koral:doc", res.at("/collection/operands/0/@type")
-                .asText());
-        assertEquals("textClass", res.at("/collection/operands/0/key").asText());
+        assertEquals("koral:doc",
+                res.at("/collection/operands/0/@type").asText());
+        assertEquals("textClass",
+                res.at("/collection/operands/0/key").asText());
         assertEquals("Sport", res.at("/collection/operands/0/value").asText());
-        assertEquals("match:eq", res.at("/collection/operands/0/match")
-                .asText());
-        assertEquals("koral:doc", res.at("/collection/operands/1/@type")
-                .asText());
+        assertEquals("match:eq",
+                res.at("/collection/operands/0/match").asText());
+        assertEquals("koral:doc",
+                res.at("/collection/operands/1/@type").asText());
         assertEquals("pubDate", res.at("/collection/operands/1/key").asText());
         assertEquals("2014", res.at("/collection/operands/1/value").asText());
-        assertEquals("type:date", res.at("/collection/operands/1/type")
-                .asText());
-        assertEquals("match:eq", res.at("/collection/operands/1/match")
-                .asText());
+        assertEquals("type:date",
+                res.at("/collection/operands/1/type").asText());
+        assertEquals("match:eq",
+                res.at("/collection/operands/1/match").asText());
 
         collection = "textClass=Sport & pubDate=2014";
         qs.setQuery(query, ql);
@@ -109,167 +104,165 @@
         res = mapper.readTree(qs.toJSON());
         assertEquals("koral:docGroup", res.at("/collection/@type").asText());
         assertEquals("operation:and", res.at("/collection/operation").asText());
-        assertEquals("koral:doc", res.at("/collection/operands/0/@type")
-                .asText());
-        assertEquals("textClass", res.at("/collection/operands/0/key").asText());
+        assertEquals("koral:doc",
+                res.at("/collection/operands/0/@type").asText());
+        assertEquals("textClass",
+                res.at("/collection/operands/0/key").asText());
         assertEquals("Sport", res.at("/collection/operands/0/value").asText());
-        assertEquals("match:eq", res.at("/collection/operands/0/match")
-                .asText());
-        assertEquals("koral:doc", res.at("/collection/operands/1/@type")
-                .asText());
+        assertEquals("match:eq",
+                res.at("/collection/operands/0/match").asText());
+        assertEquals("koral:doc",
+                res.at("/collection/operands/1/@type").asText());
         assertEquals("pubDate", res.at("/collection/operands/1/key").asText());
         assertEquals("2014", res.at("/collection/operands/1/value").asText());
-        assertEquals(true, res.at("/collection/operands/1/type")
-                .isMissingNode());
-        assertEquals("match:eq", res.at("/collection/operands/1/match")
-                .asText());
-        assertTrue(res
-                .at("/warnings/0/0")
-                .asText()
-                .startsWith(
-                        "The collection query contains a value that looks like a date"));
+        assertEquals(true,
+                res.at("/collection/operands/1/type").isMissingNode());
+        assertEquals("match:eq",
+                res.at("/collection/operands/1/match").asText());
+        assertTrue(res.at("/warnings/0/0").asText().startsWith(
+                "The collection query contains a value that looks like a date"));
     }
 
-
     @Test
-    public void testThreeConjuncts () throws JsonProcessingException,
-            IOException {
+    public void testThreeConjuncts()
+            throws JsonProcessingException, IOException {
         collection = "textClass=Sport & pubDate in 2014 & corpusId=WPD";
         qs.setQuery(query, ql);
         qs.setCollection(collection);
         res = mapper.readTree(qs.toJSON());
         assertEquals("koral:docGroup", res.at("/collection/@type").asText());
         assertEquals("operation:and", res.at("/collection/operation").asText());
-        assertEquals("koral:doc", res.at("/collection/operands/0/@type")
-                .asText());
-        assertEquals("textClass", res.at("/collection/operands/0/key").asText());
+        assertEquals("koral:doc",
+                res.at("/collection/operands/0/@type").asText());
+        assertEquals("textClass",
+                res.at("/collection/operands/0/key").asText());
         assertEquals("Sport", res.at("/collection/operands/0/value").asText());
-        assertEquals("match:eq", res.at("/collection/operands/0/match")
-                .asText());
-        assertEquals("koral:docGroup", res.at("/collection/operands/1/@type")
-                .asText());
-        assertEquals("operation:and", res
-                .at("/collection/operands/1/operation").asText());
+        assertEquals("match:eq",
+                res.at("/collection/operands/0/match").asText());
+        assertEquals("koral:docGroup",
+                res.at("/collection/operands/1/@type").asText());
+        assertEquals("operation:and",
+                res.at("/collection/operands/1/operation").asText());
         assertEquals("koral:doc",
                 res.at("/collection/operands/1/operands/0/@type").asText());
-        assertEquals("pubDate", res.at("/collection/operands/1/operands/0/key")
-                .asText());
-        assertEquals("2014", res.at("/collection/operands/1/operands/0/value")
-                .asText());
+        assertEquals("pubDate",
+                res.at("/collection/operands/1/operands/0/key").asText());
+        assertEquals("2014",
+                res.at("/collection/operands/1/operands/0/value").asText());
         assertEquals("type:date",
                 res.at("/collection/operands/1/operands/0/type").asText());
         assertEquals("match:eq",
                 res.at("/collection/operands/1/operands/0/match").asText());
         assertEquals("koral:doc",
                 res.at("/collection/operands/1/operands/1/@type").asText());
-        assertEquals("corpusId", res
-                .at("/collection/operands/1/operands/1/key").asText());
-        assertEquals("WPD", res.at("/collection/operands/1/operands/1/value")
-                .asText());
+        assertEquals("corpusId",
+                res.at("/collection/operands/1/operands/1/key").asText());
+        assertEquals("WPD",
+                res.at("/collection/operands/1/operands/1/value").asText());
         assertEquals("match:eq",
                 res.at("/collection/operands/1/operands/1/match").asText());
     }
 
-
     @Test
-    public void testTwoDisjuncts () throws JsonProcessingException, IOException {
+    public void testTwoDisjuncts() throws JsonProcessingException, IOException {
         collection = "textClass=Sport | pubDate in 2014";
         qs.setQuery(query, ql);
         qs.setCollection(collection);
         res = mapper.readTree(qs.toJSON());
         assertEquals("koral:docGroup", res.at("/collection/@type").asText());
         assertEquals("operation:or", res.at("/collection/operation").asText());
-        assertEquals("koral:doc", res.at("/collection/operands/0/@type")
-                .asText());
-        assertEquals("textClass", res.at("/collection/operands/0/key").asText());
+        assertEquals("koral:doc",
+                res.at("/collection/operands/0/@type").asText());
+        assertEquals("textClass",
+                res.at("/collection/operands/0/key").asText());
         assertEquals("Sport", res.at("/collection/operands/0/value").asText());
-        assertEquals("match:eq", res.at("/collection/operands/0/match")
-                .asText());
-        assertEquals("koral:doc", res.at("/collection/operands/1/@type")
-                .asText());
+        assertEquals("match:eq",
+                res.at("/collection/operands/0/match").asText());
+        assertEquals("koral:doc",
+                res.at("/collection/operands/1/@type").asText());
         assertEquals("pubDate", res.at("/collection/operands/1/key").asText());
         assertEquals("2014", res.at("/collection/operands/1/value").asText());
-        assertEquals("type:date", res.at("/collection/operands/1/type")
-                .asText());
-        assertEquals("match:eq", res.at("/collection/operands/1/match")
-                .asText());
+        assertEquals("type:date",
+                res.at("/collection/operands/1/type").asText());
+        assertEquals("match:eq",
+                res.at("/collection/operands/1/match").asText());
     }
 
-
     @Test
-    public void testThreeDisjuncts () throws JsonProcessingException,
-            IOException {
+    public void testThreeDisjuncts()
+            throws JsonProcessingException, IOException {
         collection = "textClass=Sport | pubDate in 2014 | corpusId=WPD";
         qs.setQuery(query, ql);
         qs.setCollection(collection);
         res = mapper.readTree(qs.toJSON());
         assertEquals("koral:docGroup", res.at("/collection/@type").asText());
         assertEquals("operation:or", res.at("/collection/operation").asText());
-        assertEquals("koral:doc", res.at("/collection/operands/0/@type")
-                .asText());
-        assertEquals("textClass", res.at("/collection/operands/0/key").asText());
+        assertEquals("koral:doc",
+                res.at("/collection/operands/0/@type").asText());
+        assertEquals("textClass",
+                res.at("/collection/operands/0/key").asText());
         assertEquals("Sport", res.at("/collection/operands/0/value").asText());
-        assertEquals("match:eq", res.at("/collection/operands/0/match")
-                .asText());
-        assertEquals("koral:docGroup", res.at("/collection/operands/1/@type")
-                .asText());
-        assertEquals("operation:or", res.at("/collection/operands/1/operation")
-                .asText());
+        assertEquals("match:eq",
+                res.at("/collection/operands/0/match").asText());
+        assertEquals("koral:docGroup",
+                res.at("/collection/operands/1/@type").asText());
+        assertEquals("operation:or",
+                res.at("/collection/operands/1/operation").asText());
         assertEquals("koral:doc",
                 res.at("/collection/operands/1/operands/0/@type").asText());
-        assertEquals("pubDate", res.at("/collection/operands/1/operands/0/key")
-                .asText());
-        assertEquals("2014", res.at("/collection/operands/1/operands/0/value")
-                .asText());
+        assertEquals("pubDate",
+                res.at("/collection/operands/1/operands/0/key").asText());
+        assertEquals("2014",
+                res.at("/collection/operands/1/operands/0/value").asText());
         assertEquals("type:date",
                 res.at("/collection/operands/1/operands/0/type").asText());
         assertEquals("match:eq",
                 res.at("/collection/operands/1/operands/0/match").asText());
         assertEquals("koral:doc",
                 res.at("/collection/operands/1/operands/1/@type").asText());
-        assertEquals("corpusId", res
-                .at("/collection/operands/1/operands/1/key").asText());
-        assertEquals("WPD", res.at("/collection/operands/1/operands/1/value")
-                .asText());
+        assertEquals("corpusId",
+                res.at("/collection/operands/1/operands/1/key").asText());
+        assertEquals("WPD",
+                res.at("/collection/operands/1/operands/1/value").asText());
         assertEquals("match:eq",
                 res.at("/collection/operands/1/operands/1/match").asText());
     }
 
-
     @Test
-    public void testMixed () throws JsonProcessingException, IOException {
+    public void testMixed() throws JsonProcessingException, IOException {
         collection = "textClass=Sport | (pubDate in 2014 & corpusId=WPD)";
         qs.setQuery(query, ql);
         qs.setCollection(collection);
         res = mapper.readTree(qs.toJSON());
         assertEquals("koral:docGroup", res.at("/collection/@type").asText());
         assertEquals("operation:or", res.at("/collection/operation").asText());
-        assertEquals("koral:doc", res.at("/collection/operands/0/@type")
-                .asText());
-        assertEquals("textClass", res.at("/collection/operands/0/key").asText());
+        assertEquals("koral:doc",
+                res.at("/collection/operands/0/@type").asText());
+        assertEquals("textClass",
+                res.at("/collection/operands/0/key").asText());
         assertEquals("Sport", res.at("/collection/operands/0/value").asText());
-        assertEquals("match:eq", res.at("/collection/operands/0/match")
-                .asText());
-        assertEquals("koral:docGroup", res.at("/collection/operands/1/@type")
-                .asText());
-        assertEquals("operation:and", res
-                .at("/collection/operands/1/operation").asText());
+        assertEquals("match:eq",
+                res.at("/collection/operands/0/match").asText());
+        assertEquals("koral:docGroup",
+                res.at("/collection/operands/1/@type").asText());
+        assertEquals("operation:and",
+                res.at("/collection/operands/1/operation").asText());
         assertEquals("koral:doc",
                 res.at("/collection/operands/1/operands/0/@type").asText());
-        assertEquals("pubDate", res.at("/collection/operands/1/operands/0/key")
-                .asText());
-        assertEquals("2014", res.at("/collection/operands/1/operands/0/value")
-                .asText());
+        assertEquals("pubDate",
+                res.at("/collection/operands/1/operands/0/key").asText());
+        assertEquals("2014",
+                res.at("/collection/operands/1/operands/0/value").asText());
         assertEquals("type:date",
                 res.at("/collection/operands/1/operands/0/type").asText());
         assertEquals("match:eq",
                 res.at("/collection/operands/1/operands/0/match").asText());
         assertEquals("koral:doc",
                 res.at("/collection/operands/1/operands/1/@type").asText());
-        assertEquals("corpusId", res
-                .at("/collection/operands/1/operands/1/key").asText());
-        assertEquals("WPD", res.at("/collection/operands/1/operands/1/value")
-                .asText());
+        assertEquals("corpusId",
+                res.at("/collection/operands/1/operands/1/key").asText());
+        assertEquals("WPD",
+                res.at("/collection/operands/1/operands/1/value").asText());
         assertEquals("match:eq",
                 res.at("/collection/operands/1/operands/1/match").asText());
 
@@ -279,32 +272,33 @@
         res = mapper.readTree(qs.toJSON());
         assertEquals("koral:docGroup", res.at("/collection/@type").asText());
         assertEquals("operation:or", res.at("/collection/operation").asText());
-        assertEquals("koral:doc", res.at("/collection/operands/0/@type")
-                .asText());
-        assertEquals("textClass", res.at("/collection/operands/0/key").asText());
+        assertEquals("koral:doc",
+                res.at("/collection/operands/0/@type").asText());
+        assertEquals("textClass",
+                res.at("/collection/operands/0/key").asText());
         assertEquals("Sport", res.at("/collection/operands/0/value").asText());
-        assertEquals("match:eq", res.at("/collection/operands/0/match")
-                .asText());
-        assertEquals("koral:docGroup", res.at("/collection/operands/1/@type")
-                .asText());
-        assertEquals("operation:and", res
-                .at("/collection/operands/1/operation").asText());
+        assertEquals("match:eq",
+                res.at("/collection/operands/0/match").asText());
+        assertEquals("koral:docGroup",
+                res.at("/collection/operands/1/@type").asText());
+        assertEquals("operation:and",
+                res.at("/collection/operands/1/operation").asText());
         assertEquals("koral:doc",
                 res.at("/collection/operands/1/operands/0/@type").asText());
-        assertEquals("pubDate", res.at("/collection/operands/1/operands/0/key")
-                .asText());
-        assertEquals("2014", res.at("/collection/operands/1/operands/0/value")
-                .asText());
+        assertEquals("pubDate",
+                res.at("/collection/operands/1/operands/0/key").asText());
+        assertEquals("2014",
+                res.at("/collection/operands/1/operands/0/value").asText());
         assertEquals("type:date",
                 res.at("/collection/operands/1/operands/0/type").asText());
         assertEquals("match:eq",
                 res.at("/collection/operands/1/operands/0/match").asText());
         assertEquals("koral:doc",
                 res.at("/collection/operands/1/operands/1/@type").asText());
-        assertEquals("corpusId", res
-                .at("/collection/operands/1/operands/1/key").asText());
-        assertEquals("WPD", res.at("/collection/operands/1/operands/1/value")
-                .asText());
+        assertEquals("corpusId",
+                res.at("/collection/operands/1/operands/1/key").asText());
+        assertEquals("WPD",
+                res.at("/collection/operands/1/operands/1/value").asText());
         assertEquals("match:eq",
                 res.at("/collection/operands/1/operands/1/match").asText());
 
@@ -314,16 +308,16 @@
         res = mapper.readTree(qs.toJSON());
         assertEquals("koral:docGroup", res.at("/collection/@type").asText());
         assertEquals("operation:and", res.at("/collection/operation").asText());
-        assertEquals("koral:docGroup", res.at("/collection/operands/0/@type")
-                .asText());
-        assertEquals("operation:or", res.at("/collection/operands/0/operation")
-                .asText());
+        assertEquals("koral:docGroup",
+                res.at("/collection/operands/0/@type").asText());
+        assertEquals("operation:or",
+                res.at("/collection/operands/0/operation").asText());
         assertEquals("koral:doc",
                 res.at("/collection/operands/0/operands/0/@type").asText());
         assertEquals("koral:doc",
                 res.at("/collection/operands/0/operands/1/@type").asText());
-        assertEquals("koral:doc", res.at("/collection/operands/1/@type")
-                .asText());
+        assertEquals("koral:doc",
+                res.at("/collection/operands/1/@type").asText());
 
         collection = "(textClass=Sport & pubDate in 2014) & corpusId=WPD";
         qs.setQuery(query, ql);
@@ -331,16 +325,16 @@
         res = mapper.readTree(qs.toJSON());
         assertEquals("koral:docGroup", res.at("/collection/@type").asText());
         assertEquals("operation:and", res.at("/collection/operation").asText());
-        assertEquals("koral:docGroup", res.at("/collection/operands/0/@type")
-                .asText());
-        assertEquals("operation:and", res
-                .at("/collection/operands/0/operation").asText());
+        assertEquals("koral:docGroup",
+                res.at("/collection/operands/0/@type").asText());
+        assertEquals("operation:and",
+                res.at("/collection/operands/0/operation").asText());
         assertEquals("koral:doc",
                 res.at("/collection/operands/0/operands/0/@type").asText());
         assertEquals("koral:doc",
                 res.at("/collection/operands/0/operands/1/@type").asText());
-        assertEquals("koral:doc", res.at("/collection/operands/1/@type")
-                .asText());
+        assertEquals("koral:doc",
+                res.at("/collection/operands/1/@type").asText());
 
         collection = "(textClass=Sport & textClass=ausland) | (corpusID=WPD & author=White)";
         qs.setQuery(query, ql);
@@ -348,30 +342,30 @@
         res = mapper.readTree(qs.toJSON());
         assertEquals("koral:docGroup", res.at("/collection/@type").asText());
         assertEquals("operation:or", res.at("/collection/operation").asText());
-        assertEquals("koral:docGroup", res.at("/collection/operands/0/@type")
-                .asText());
-        assertEquals("operation:and", res
-                .at("/collection/operands/0/operation").asText());
-        assertEquals("koral:docGroup", res.at("/collection/operands/1/@type")
-                .asText());
-        assertEquals("operation:and", res
-                .at("/collection/operands/1/operation").asText());
+        assertEquals("koral:docGroup",
+                res.at("/collection/operands/0/@type").asText());
+        assertEquals("operation:and",
+                res.at("/collection/operands/0/operation").asText());
+        assertEquals("koral:docGroup",
+                res.at("/collection/operands/1/@type").asText());
+        assertEquals("operation:and",
+                res.at("/collection/operands/1/operation").asText());
         assertEquals("koral:doc",
                 res.at("/collection/operands/0/operands/0/@type").asText());
-        assertEquals("Sport", res.at("/collection/operands/0/operands/0/value")
-                .asText());
+        assertEquals("Sport",
+                res.at("/collection/operands/0/operands/0/value").asText());
         assertEquals("koral:doc",
                 res.at("/collection/operands/0/operands/1/@type").asText());
         assertEquals("ausland",
                 res.at("/collection/operands/0/operands/1/value").asText());
         assertEquals("koral:doc",
                 res.at("/collection/operands/1/operands/0/@type").asText());
-        assertEquals("WPD", res.at("/collection/operands/1/operands/0/value")
-                .asText());
+        assertEquals("WPD",
+                res.at("/collection/operands/1/operands/0/value").asText());
         assertEquals("koral:doc",
                 res.at("/collection/operands/1/operands/1/@type").asText());
-        assertEquals("White", res.at("/collection/operands/1/operands/1/value")
-                .asText());
+        assertEquals("White",
+                res.at("/collection/operands/1/operands/1/value").asText());
 
         collection = "(textClass=Sport & textClass=ausland) | (corpusID=WPD & author=White & pubDate in 2000)";
         qs.setQuery(query, ql);
@@ -379,26 +373,26 @@
         res = mapper.readTree(qs.toJSON());
         assertEquals("koral:docGroup", res.at("/collection/@type").asText());
         assertEquals("operation:or", res.at("/collection/operation").asText());
-        assertEquals("koral:docGroup", res.at("/collection/operands/0/@type")
-                .asText());
-        assertEquals("operation:and", res
-                .at("/collection/operands/0/operation").asText());
-        assertEquals("koral:docGroup", res.at("/collection/operands/1/@type")
-                .asText());
-        assertEquals("operation:and", res
-                .at("/collection/operands/1/operation").asText());
+        assertEquals("koral:docGroup",
+                res.at("/collection/operands/0/@type").asText());
+        assertEquals("operation:and",
+                res.at("/collection/operands/0/operation").asText());
+        assertEquals("koral:docGroup",
+                res.at("/collection/operands/1/@type").asText());
+        assertEquals("operation:and",
+                res.at("/collection/operands/1/operation").asText());
         assertEquals("koral:doc",
                 res.at("/collection/operands/0/operands/0/@type").asText());
-        assertEquals("Sport", res.at("/collection/operands/0/operands/0/value")
-                .asText());
+        assertEquals("Sport",
+                res.at("/collection/operands/0/operands/0/value").asText());
         assertEquals("koral:doc",
                 res.at("/collection/operands/0/operands/1/@type").asText());
         assertEquals("ausland",
                 res.at("/collection/operands/0/operands/1/value").asText());
         assertEquals("koral:doc",
                 res.at("/collection/operands/1/operands/0/@type").asText());
-        assertEquals("WPD", res.at("/collection/operands/1/operands/0/value")
-                .asText());
+        assertEquals("WPD",
+                res.at("/collection/operands/1/operands/0/value").asText());
         assertEquals("koral:docGroup",
                 res.at("/collection/operands/1/operands/1/@type").asText());
         assertEquals("operation:and",
@@ -411,9 +405,8 @@
                         .asText());
     }
 
-
     @Test
-    public void testDateYear () throws JsonProcessingException, IOException {
+    public void testDateYear() throws JsonProcessingException, IOException {
         collection = "pubDate in 2000";
         qs.setQuery(query, ql);
         qs.setCollection(collection);
@@ -455,9 +448,8 @@
         assertEquals("match:leq", res.at("/collection/match").asText());
     }
 
-
     @Test
-    public void testDateMonthDay () throws JsonProcessingException, IOException {
+    public void testDateMonthDay() throws JsonProcessingException, IOException {
         collection = "pubDate in 2000-02";
         qs.setQuery(query, ql);
         qs.setCollection(collection);