diff --git a/src/main/java/org/gcube/informationsystem/discovery/Discovery.java b/src/main/java/org/gcube/informationsystem/discovery/Discovery.java
index dd6f437..60912dd 100644
--- a/src/main/java/org/gcube/informationsystem/discovery/Discovery.java
+++ b/src/main/java/org/gcube/informationsystem/discovery/Discovery.java
@@ -80,6 +80,10 @@ public class Discovery<E extends Element> {
 		}
 	}
 	
+	public void addRegistrationProvider(RegistrationProvider registrationProvider) {
+		addPackages(registrationProvider.getPackagesToRegister());
+	}
+	
 	@SuppressWarnings("unchecked")
 	protected void add(Class<E> clz) throws Exception {
 		if(!discoveredElement.contains(clz)) {
diff --git a/src/main/java/org/gcube/informationsystem/discovery/knowledge/ModelExtensionKnowledge.java b/src/main/java/org/gcube/informationsystem/discovery/knowledge/ModelExtensionKnowledge.java
index a01bf03..43fe59b 100644
--- a/src/main/java/org/gcube/informationsystem/discovery/knowledge/ModelExtensionKnowledge.java
+++ b/src/main/java/org/gcube/informationsystem/discovery/knowledge/ModelExtensionKnowledge.java
@@ -37,7 +37,7 @@ public class ModelExtensionKnowledge {
 			AddElementToTreeAction aetta = new AddElementToTreeAction(tree);
 			
 			Discovery<? extends Element> discovery = new Discovery<>(clz, false);
-			discovery.addPackages(registrationProvider.getPackagesToRegister());
+			discovery.addRegistrationProvider(registrationProvider);
 			discovery.addDiscoveredElementActions(new ElementMappingAction());
 			discovery.addDiscoveredElementActions(aetta);
 			
diff --git a/src/main/java/org/gcube/informationsystem/discovery/knowledge/ModelKnowledge.java b/src/main/java/org/gcube/informationsystem/discovery/knowledge/ModelKnowledge.java
new file mode 100644
index 0000000..3456231
--- /dev/null
+++ b/src/main/java/org/gcube/informationsystem/discovery/knowledge/ModelKnowledge.java
@@ -0,0 +1,18 @@
+package org.gcube.informationsystem.discovery.knowledge;
+
+import java.util.Map;
+
+import org.gcube.informationsystem.base.reference.AccessType;
+import org.gcube.informationsystem.base.reference.Element;
+import org.gcube.informationsystem.tree.Tree;
+
+/**
+ * @author Luca Frosini (ISTI - CNR)
+ */
+public class ModelKnowledge {
+
+	protected Map<AccessType, Tree<Class<Element>>> trees;
+	
+	
+	
+}
diff --git a/src/main/java/org/gcube/informationsystem/serialization/ElementMapper.java b/src/main/java/org/gcube/informationsystem/serialization/ElementMapper.java
index 1e11fd1..a882918 100644
--- a/src/main/java/org/gcube/informationsystem/serialization/ElementMapper.java
+++ b/src/main/java/org/gcube/informationsystem/serialization/ElementMapper.java
@@ -101,7 +101,7 @@ public abstract class ElementMapper {
 	}
 	
 	public static void registerPackages(List<Package> packages) {
-		DiscoveredElementAction schemaAction = new ElementMappingAction();
+		DiscoveredElementAction<Element> schemaAction = new ElementMappingAction();
 		try {
 			DiscoveryUtility.manageISM(schemaAction, packages);
 		} catch(Exception e) {
diff --git a/src/main/java/org/gcube/informationsystem/types/knowledge/Node.java b/src/main/java/org/gcube/informationsystem/types/knowledge/toBeRemoved/Node.java
similarity index 97%
rename from src/main/java/org/gcube/informationsystem/types/knowledge/Node.java
rename to src/main/java/org/gcube/informationsystem/types/knowledge/toBeRemoved/Node.java
index 24fe005..b8d077d 100644
--- a/src/main/java/org/gcube/informationsystem/types/knowledge/Node.java
+++ b/src/main/java/org/gcube/informationsystem/types/knowledge/toBeRemoved/Node.java
@@ -1,4 +1,4 @@
-package org.gcube.informationsystem.types.knowledge;
+package org.gcube.informationsystem.types.knowledge.toBeRemoved;
 
 import java.util.Set;
 import java.util.TreeSet;
diff --git a/src/main/java/org/gcube/informationsystem/types/knowledge/NodeElaborator.java b/src/main/java/org/gcube/informationsystem/types/knowledge/toBeRemoved/NodeElaborator.java
similarity index 69%
rename from src/main/java/org/gcube/informationsystem/types/knowledge/NodeElaborator.java
rename to src/main/java/org/gcube/informationsystem/types/knowledge/toBeRemoved/NodeElaborator.java
index 09a1767..5adb4bf 100644
--- a/src/main/java/org/gcube/informationsystem/types/knowledge/NodeElaborator.java
+++ b/src/main/java/org/gcube/informationsystem/types/knowledge/toBeRemoved/NodeElaborator.java
@@ -1,4 +1,4 @@
-package org.gcube.informationsystem.types.knowledge;
+package org.gcube.informationsystem.types.knowledge.toBeRemoved;
 
 /**
  * @author Luca Frosini (ISTI - CNR)
diff --git a/src/main/java/org/gcube/informationsystem/types/knowledge/Tree.java b/src/main/java/org/gcube/informationsystem/types/knowledge/toBeRemoved/Tree.java
similarity index 96%
rename from src/main/java/org/gcube/informationsystem/types/knowledge/Tree.java
rename to src/main/java/org/gcube/informationsystem/types/knowledge/toBeRemoved/Tree.java
index bcb59b3..926e957 100644
--- a/src/main/java/org/gcube/informationsystem/types/knowledge/Tree.java
+++ b/src/main/java/org/gcube/informationsystem/types/knowledge/toBeRemoved/Tree.java
@@ -1,4 +1,4 @@
-package org.gcube.informationsystem.types.knowledge;
+package org.gcube.informationsystem.types.knowledge.toBeRemoved;
 
 import java.util.HashMap;
 import java.util.Set;
diff --git a/src/main/java/org/gcube/informationsystem/types/knowledge/UsageKnowledge.java b/src/main/java/org/gcube/informationsystem/types/knowledge/toBeRemoved/UsageKnowledge.java
similarity index 96%
rename from src/main/java/org/gcube/informationsystem/types/knowledge/UsageKnowledge.java
rename to src/main/java/org/gcube/informationsystem/types/knowledge/toBeRemoved/UsageKnowledge.java
index 2e256a3..05fa384 100644
--- a/src/main/java/org/gcube/informationsystem/types/knowledge/UsageKnowledge.java
+++ b/src/main/java/org/gcube/informationsystem/types/knowledge/toBeRemoved/UsageKnowledge.java
@@ -1,4 +1,4 @@
-package org.gcube.informationsystem.types.knowledge;
+package org.gcube.informationsystem.types.knowledge.toBeRemoved;
 
 import java.util.Collection;
 import java.util.LinkedHashMap;