public boolean isInstance(Object object)
  {
    if (object != null)
    {
      Class<?> instanceClass = getInstanceClass();
      if (instanceClass != null)
      {
        if (instanceClass.isPrimitive())
        {
          ...
        }
        else
        {
          return instanceClass.isInstance(object); // as object is a DynamicEObject,  this will (wrongly) return false
        }
      }
      else if (object instanceof EObject)
      {
        return dynamicIsInstance((EObject)object);
      }
    }
    return false;
  }

public class EdaptMigrationFactory extends EFactoryImpl {
  @Override
  public EObject create(EClass eClass) {
    if (eClass.getInstanceClass() != java.util.Map.Entry.class) // EMF's map entries are correctly handled
      eClass.setInstanceClass(null);
    return super.create(eClass);
  }