code: def _validate_non_edges_do_not_have_edge_like_properties(class_name, properties):
      
      has_source = EDGE_SOURCE_PROPERTY_NAME in properties
      has_destination = EDGE_DESTINATION_PROPERTY_NAME in properties
  
      if has_source or has_destination:
          raise IllegalSchemaStateError(u'Found a non-edge class that defines edge-like "in" or '
                                        u'"out" properties: {} {}'.format(class_name, properties))
  
      for property_name, property_descriptor in six.iteritems(properties):
          if property_descriptor.type_id == PROPERTY_TYPE_LINK_ID:
              raise IllegalSchemaStateError(u'Non-edge class "{}" has a property of type Link, this '
                                            u'is not allowed: {}'.format(class_name, property_name))
docs: Validate that non-edges do not have the in/out properties defined.