Which EClass is the diagram root element?
GMF requires an EClass which corresponds to the diagram root element. In Reflective Ecore Model Diagram Editor, the root element has to be determined dynamically. If .xsd files is given as a meta-model, the type of the root element defined in the XSD is chosen as the diagram root element. In the case of .ecore file, the creation wizard asks after loading the dynamic Ecore.