diff --git a/src/main/java/de/ids_mannheim/korap/query/serialize/IdWriter.java b/src/main/java/de/ids_mannheim/korap/query/serialize/IdWriter.java
index 70d6a31..966b3d3 100644
--- a/src/main/java/de/ids_mannheim/korap/query/serialize/IdWriter.java
+++ b/src/main/java/de/ids_mannheim/korap/query/serialize/IdWriter.java
@@ -1,24 +1,26 @@
 package de.ids_mannheim.korap.query.serialize;
 
+import com.fasterxml.jackson.core.JsonProcessingException;
 import com.fasterxml.jackson.databind.JsonNode;
+import com.fasterxml.jackson.databind.ObjectMapper;
 import com.fasterxml.jackson.databind.node.ObjectNode;
-import de.ids_mannheim.korap.utils.JsonUtils;
 
 import java.util.Iterator;
 
 /**
  * @author hanl
  * @date 04/06/2014
- *       <p/>
- *       create idn for korap:token
+ * <p/>
+ * create idn for korap:token
  */
 public class IdWriter {
 
     private JsonNode node;
     private int counter;
+    private ObjectMapper mapper = new ObjectMapper();
 
-    public IdWriter (String json) {
-        node = JsonUtils.readTree(json);
+    public IdWriter(String json) {
+        node = mapper.valueToTree(json);
         counter = 0;
     }
 
@@ -63,13 +65,17 @@
 
     }
 
-    @Deprecated
-    public JsonNode getFinalNode() {
+    @Deprecated public JsonNode getFinalNode() {
         return this.node;
     }
 
     public String toJSON() {
-        return JsonUtils.toJSON(node);
+        try {
+            return mapper.writeValueAsString(node);
+        }
+        catch (JsonProcessingException e) {
+            return "";
+        }
     }
 
 }
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 d62b622..b0af534 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
@@ -65,7 +65,6 @@
             try {
                 System.out.println(q);
                 String ql = "cosmas2";
-                jg.setCollection("pubDate=2014");
                 jg.run(q, ql);
                 System.out.println();
             }
@@ -253,12 +252,12 @@
         return this;
     }
 
-    @Deprecated public QuerySerializer setCollectionSimple(String collection) {
-        CollectionQueryBuilder qobj = new CollectionQueryBuilder();
-        qobj.addResource(collection);
-        this.collection = (Map<String, Object>) qobj.raw();
-        return this;
-    }
+//    @Deprecated public QuerySerializer setCollectionSimple(String collection) {
+//        CollectionQueryBuilder qobj = new CollectionQueryBuilder();
+//        qobj.addResource(collection);
+//        this.collection = (Map<String, Object>) qobj.raw();
+//        return this;
+//    }
 
     public QuerySerializer setCollection(String collection) {
         CollectionQueryProcessor tree = new CollectionQueryProcessor();
@@ -272,14 +271,14 @@
         return this;
     }
 
-    public QuerySerializer setCollection(CollectionQueryBuilder2 collections) {
-        this.collection = (Map<String, Object>) collections.raw();
-        return this;
-    }
-
-    public QuerySerializer setDeprCollection(
-            CollectionQueryBuilder collections) {
-        this.collection = (Map<String, Object>) collections.raw();
-        return this;
-    }
+//    public QuerySerializer setCollection(CollectionQueryBuilder2 collections) {
+    //        this.collection = (Map<String, Object>) collections.raw();
+    //        return this;
+    //    }
+    //
+    //    public QuerySerializer setDeprCollection(
+    //            CollectionQueryBuilder collections) {
+    //        this.collection = (Map<String, Object>) collections.raw();
+    //        return this;
+    //    }
 }
diff --git a/src/test/java/MetaQuerySerializationTest.java b/src/test/java/MetaQuerySerializationTest.java
deleted file mode 100644
index a2e6442..0000000
--- a/src/test/java/MetaQuerySerializationTest.java
+++ /dev/null
@@ -1,200 +0,0 @@
-import com.fasterxml.jackson.core.JsonGenerationException;
-import com.fasterxml.jackson.core.JsonProcessingException;
-import com.fasterxml.jackson.databind.JsonMappingException;
-import de.ids_mannheim.korap.query.serialize.CollectionQueryBuilder;
-import de.ids_mannheim.korap.query.serialize.QuerySerializer;
-import de.ids_mannheim.korap.query.serialize.util.QueryException;
-import org.junit.Assert;
-import org.junit.Test;
-import org.junit.runner.RunWith;
-import org.junit.runners.JUnit4;
-
-import java.io.IOException;
-
-/**
- * @author hanl
- * @date 04/12/2013
- */
-
-@RunWith(JUnit4.class)
-public class MetaQuerySerializationTest {
-
-
-    @Test
-    public void test() throws IOException {
-        StringBuffer b = new StringBuffer();
-        b.append("author:Goethe");
-        b.append(" AND ");
-        b.append("pubPlace:Erfurt");
-        b.append(" AND ");
-        b.append("textClass:wissenschaft");
-//        CollectionQuery qu = new CollectionQuery().addMetaFilterQuery(b.toString());
-        CollectionQueryBuilder query = new CollectionQueryBuilder().addMetaFilterQuery(b.toString());
-        System.out.println(query.toJSON());
-        System.out.println(query.toCollections());
-//        System.out.println("value reference " + qu.stringify());
-//        System.out.println();
-    }
-
-    @Test
-    public void testSingle() throws IOException {
-        CollectionQueryBuilder query = new CollectionQueryBuilder().addMetaFilter("textClass", "wissenschaft");
-//        System.out.println("------ TEXT SINGLE " + query.stringify());
-        System.out.println(query.toJSON());
-    }
-
-//    @Test
-    public void testDates() throws IOException {
-        StringBuffer b = new StringBuffer();
-        b.append("pubDate:>2013-04-01");
-        b.append(" AND ");
-        b.append("pubDate:<2012-04-01");
-        b.append(" AND ");
-        b.append("author:Goethe");
-        CollectionQueryBuilder query = new CollectionQueryBuilder().addMetaFilterQuery(b.toString());
-        System.out.println("value until/since : " + query.toJSON());
-        System.out.println("meta value until/since " + query.toCollections());
-        Assert.assertEquals("[{\"@type\":\"korap:meta-filter\",\"@value\":{\"@type\":\"korap:group\",\"relation\":\"and\",\"operands\":[{\"@type\":\"korap:term\",\"@field\":\"korap:field#author\",\"@value\":\"Goethe\"},{\"@type\":\"korap:group\",\"@field\":\"korap:field#pubDate\",\"relation\":\"between\",\"operands\":[{\"@type\":\"korap:date\",\"@value\":\"2012-04-01\"},{\"@type\":\"korap:date\",\"@value\":\"2013-04-01\"}]}]}}]", query.toJSON());
-//        System.out.println();
-    }
-
-//    @Test
-    public void testUntil() throws IOException {
-        StringBuffer b = new StringBuffer();
-        b.append("pubDate:>2013-12-10");
-        b.append(" AND ");
-        b.append("author:Hesse");
-        CollectionQueryBuilder query = new CollectionQueryBuilder().addMetaFilterQuery(b.toString());
-        System.out.println("Running date check (until) with additional attribute author");
-        Assert.assertEquals("[{\"@type\":\"korap:meta-filter\",\"@value\":{\"@type\":\"korap:group\",\"relation\":\"and\",\"operands\":[{\"@type\":\"korap:term\",\"@field\":\"korap:field#author\",\"@value\":\"Hesse\"},{\"@type\":\"korap:group\",\"@field\":\"korap:field#pubDate\",\"relation\":\"until\",\"operands\":[{\"@type\":\"korap:date\",\"@value\":\"2013-12-10\"}]}]}}]", query.toJSON());
-//        System.out.println("value until : " + query.stringify());
-//        System.out.println();
-    }
-
-//    @Test
-    public void testSince() throws IOException {
-        StringBuffer b = new StringBuffer();
-        b.append("pubDate:<2013-12-10");
-        b.append(" AND ");
-        b.append("author:Kafka");
-        CollectionQueryBuilder query = new CollectionQueryBuilder().addMetaFilterQuery(b.toString());
-        System.out.println("value since : " + query.toJSON());
-        System.out.println("meta value since " + query.toCollections());
-//        System.out.println();
-        System.out.println("Running date check (since) with additional attribute author");
-        Assert.assertEquals("[{\"@type\":\"korap:meta-filter\",\"@value\":{\"@type\":\"korap:group\",\"relation\":\"and\",\"operands\":[{\"@type\":\"korap:term\",\"@field\":\"korap:field#author\",\"@value\":\"Kafka\"},{\"@type\":\"korap:group\",\"@field\":\"korap:field#pubDate\",\"relation\":\"since\",\"operands\":[{\"@type\":\"korap:date\",\"@value\":\"2013-12-10\"}]}]}}]", query.toJSON());
-    }
-
-
-    @Test
-    public void testMeta() {
-        QuerySerializer s = new QuerySerializer();
-        try {
-            s.setQuery("shrink({[base=foo]})", "poliqarp");
-            s.addMeta("2-token, 2-token", 10, 0);
-        } catch (QueryException e) {
-            e.printStackTrace();
-        }
-        System.out.println("THE RESULTING QUERY: " + s.toJSON());
-    }
-
-//    //    @Test
-//    public void testGenerator() throws QueryException {
-//         /*
-//         * just for testing...
-//		 */
-//        QuerySerializer jg = new QuerySerializer();
-//        int i = 0;
-//        String[] queries;
-//        queries = new String[]{
-//                "shrink({[base=foo]})",
-//                "shrink({[base=foo]}[orth=bar])",
-//                "shrink(1:[base=Der]{1:[base=Mann]})",
-//        };
-//
-//        for (String q : queries) {
-//            i++;
-//            try {
-//                System.out.println(q);
-//                jg.run(q, "poliqarp", System.getProperty("user.home") + "/bsp" + i + ".json");
-//                System.out.println();
-//            } catch (NullPointerException npe) {
-//                npe.printStackTrace();
-//                System.out.println("null\n");
-//                System.out.println();
-//            } catch (JsonGenerationException e) {
-//                e.printStackTrace();
-//            } catch (JsonMappingException e) {
-//                e.printStackTrace();
-//            } catch (IOException e) {
-//                e.printStackTrace();
-//            }
-//        }
-//    }
-
-    @Test
-    public void testLists() {
-        StringBuffer b = new StringBuffer();
-        b.append("pubDate:<2013-12-10");
-        b.append(" AND ");
-        b.append("author:Kafka");
-        CollectionQueryBuilder q = new CollectionQueryBuilder().addMetaFilterQuery(b.toString());
-        q.addMetaExtend("author", "Hesse");
-
-        System.out.println("--- ALL " + q.toJSON());
-        System.out.println();
-
-    }
-
-    @Test
-    public void testJSONArray() throws JsonProcessingException {
-        StringBuffer b = new StringBuffer();
-        b.append("pubDate:<2013-12-10");
-        b.append(" AND ");
-        b.append("author:Kafka");
-        CollectionQueryBuilder q = new CollectionQueryBuilder().addMetaExtendQuery(b.toString());
-        System.out.println("array repres " + q.toJSON());
-        System.out.println();
-    }
-
-    @Test
-    public void testCollections() throws IOException {
-        CollectionQueryBuilder q = new CollectionQueryBuilder().addMetaFilter("corpusID", "A00");
-        q.addMetaExtend("corpusID", "A01");
-
-        System.out.println("results stringified " + q.toJSON());
-        System.out.println("results to meta" + q.toCollections());
-        System.out.println();
-    }
-
-    /**
-     * asserts equality. input should be equal to output,
-     * since there is no other metadata added to the meta query
-     *
-     * @throws IOException
-     */
-    @Test
-    public void testResources() throws IOException {
-        String meta = "[{\"@type\":\"korap:meta-filter\",\"@value\":{\"@type\":\"korap:term\",\"@field\":\"korap:field#corpusID\",\"@value\":\"WPD\"}}]";
-        CollectionQueryBuilder q = new CollectionQueryBuilder().addResource(meta);
-        System.out.println("Testing Resource Meta data");
-        org.junit.Assert.assertEquals("{\"collections\":" + meta + "}", q.toCollections());
-    }
-
-    @Test
-    public void testA00() throws IOException {
-        CollectionQueryBuilder q = new CollectionQueryBuilder().addMetaExtend("corpusID", "A00").addMetaExtend("corpusID", "A01");
-        System.out.println("A meta: " + q.toJSON());
-        System.out.println();
-    }
-
-    @Test
-    public void testResources2() throws IOException {
-        String meta = "[{\"@type\":\"korap:meta-filter\",\"@value\":{\"@type\":\"korap:term\",\"@field\":\"korap:field#corpusID\",\"@value\":\"WPD\"}}]";
-        CollectionQueryBuilder q = new CollectionQueryBuilder().addResource(meta);
-        q.addMetaFilter("textClass", "wissenschaft");
-        System.out.println("stringified meta " + q.toJSON());
-        System.out.println("meta string " + q.toCollections());
-    }
-
-}