diff --git a/src/test/java/MetaQuerySerializationTest.java b/src/test/java/MetaQuerySerializationTest.java
index 99fb774..ccd0011 100644
--- a/src/test/java/MetaQuerySerializationTest.java
+++ b/src/test/java/MetaQuerySerializationTest.java
@@ -1,3 +1,6 @@
+import com.fasterxml.jackson.core.JsonGenerationException;
+import com.fasterxml.jackson.databind.JsonMappingException;
+import de.ids_mannheim.korap.query.serialize.JsonGenerator;
 import de.ids_mannheim.korap.query.serialize.MetaCollectionSerializer;
 import de.ids_mannheim.korap.query.serialize.MetaQuerySerializer;
 import org.joda.time.DateTime;
@@ -41,29 +44,29 @@
         Map<String, String> j = new HashMap();
         j.put("textClass", "wissenschaft");
         String s = querySerializer.stringify(j, MetaQuerySerializer.TYPE.FILTER);
-//        System.out.println("value reference test single " + s);
+        System.out.println("------ TEXT SINGLE " + s);
     }
 
     @Test
     public void testResourceMeta() throws IOException {
         String s = collSerializer.serialize("25");
-//        System.out.println(" --- RESULT JSON " + s);
+        System.out.println(" --- RESULT JSON " + s);
     }
 
     @Test
     public void testDates() throws IOException {
         Map<String, String> queries = new LinkedHashMap<>();
-        queries.put("<pubDate", String.valueOf(new DateTime().getMillis()));
-        queries.put(">pubDate", String.valueOf(new DateTime().getMillis() + 2));
+        queries.put("pubDate", String.valueOf(new DateTime().getMillis()) + "~"
+                + String.valueOf(new DateTime().getMillis() + 2));
         queries.put("author", "Goethe");
         String f = querySerializer.stringify(queries, MetaQuerySerializer.TYPE.FILTER);
-//        System.out.println("value : "+ f);
+        System.out.println("value until/since : " + f);
     }
 
     @Test
     public void testUntil() throws IOException {
         Map<String, String> queries = new LinkedHashMap<>();
-        queries.put(">pubDate", String.valueOf(new DateTime().getMillis()));
+        queries.put("pubDate", ">" + String.valueOf(new DateTime().getMillis()));
         queries.put("author", "Hesse");
         String f = querySerializer.stringify(queries, MetaQuerySerializer.TYPE.FILTER);
         System.out.println("value until : " + f);
@@ -72,10 +75,43 @@
     @Test
     public void testSince() throws IOException {
         Map<String, String> queries = new LinkedHashMap<>();
-        queries.put("<pubDate", String.valueOf(new DateTime().getMillis()));
+        queries.put("pubDate", "<" + String.valueOf(new DateTime().getMillis()));
         queries.put("author", "Kafka");
         String f = querySerializer.stringify(queries, MetaQuerySerializer.TYPE.FILTER);
         System.out.println("value since : " + f);
     }
 
+    //@Test
+    public void testGenerator() {
+                   /*
+         * just for testing...
+		 */
+        JsonGenerator jg = new JsonGenerator();
+        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");
+            } catch (JsonGenerationException e) {
+                e.printStackTrace();
+            } catch (JsonMappingException e) {
+                e.printStackTrace();
+            } catch (IOException e) {
+                e.printStackTrace();
+            }
+        }
+    }
+
 }