diff --git a/src/test/java/org/gcube/informationsystem/resourceregistry/client/ResourceRegistryClientTestWikiExamples.java b/src/test/java/org/gcube/informationsystem/resourceregistry/client/ResourceRegistryClientTestWikiExamples.java
index fdfc57e..8cb2b64 100644
--- a/src/test/java/org/gcube/informationsystem/resourceregistry/client/ResourceRegistryClientTestWikiExamples.java
+++ b/src/test/java/org/gcube/informationsystem/resourceregistry/client/ResourceRegistryClientTestWikiExamples.java
@@ -9,6 +9,7 @@ import java.util.Map;
 import java.util.UUID;
 
 import org.gcube.informationsystem.base.reference.Direction;
+import org.gcube.informationsystem.base.reference.Element;
 import org.gcube.informationsystem.model.reference.entities.Resource;
 import org.gcube.informationsystem.model.reference.relations.ConsistsOf;
 import org.gcube.informationsystem.resourceregistry.api.exceptions.ResourceRegistryException;
@@ -208,23 +209,23 @@ public class ResourceRegistryClientTestWikiExamples extends ContextTest {
 	@Test
 	public void jsonQueryExample1() throws ResourceRegistryException, Exception{
 		String jsonQuery = "{\n"
-				+ "	\"@class\": \"EService\",\n"
+				+ "	\"" + Element.CLASS_PROPERTY + "\": \"EService\",\n"
 				+ "	\"consistsOf\": [\n"
 				+ "		{\n"
-				+ "			\"@class\": \"IsIdentifiedBy\",\n"
+				+ "			\"" + Element.CLASS_PROPERTY + "\": \"IsIdentifiedBy\",\n"
 				+ "			\"target\": {\n"
-				+ "				\"@class\": \"SoftwareFacet\",\n"
+				+ "				\"" + Element.CLASS_PROPERTY + "\": \"SoftwareFacet\",\n"
 				+ "				\"group\": \"DataTransfer\",\n"
 				+ "				\"name\": \"data-transfer-service\"\n"
 				+ "			}\n"
 				+ "		}\n"
 				+ "		{\n"
-				+ "			\"@class\": \"ConsistsOf\",\n"
+				+ "			\"" + Element.CLASS_PROPERTY + "\": \"ConsistsOf\",\n"
 				+ "			\"target\": {\n"
-				+ "				\"@class\": \"StateFacet\",\n"
+				+ "				\"" + Element.CLASS_PROPERTY + "\": \"StateFacet\",\n"
 				+ "				\"value\": \"down\"\n"
 				+ "			}\n"
-				+ "		},\n"
+				+ "		}\n"
 				+ " \n"
 				+ "	]\n"
 				+ "}";