Added missing method in interface

src/main/java/org/gcube/informationsystem/base/reference/Attribute.java

@@ -1,5 +1,8 @@
 package org.gcube.informationsystem.base.reference;
 
+import org.gcube.com.fasterxml.jackson.annotation.JsonIgnore;
+import org.gcube.informationsystem.types.PropertyTypeName;
+
 /**
  * @author Luca Frosini (ISTI - CNR)
  */
@@ -27,6 +30,9 @@ public interface Attribute {
 	
 	public void setPropertyType(String type);
 	
+	@JsonIgnore
+	public PropertyTypeName getPropertyTypeName();
+	
 	public Object getDefaultValue();
 
 	public void setDefaultValue(Object defaultValue);