code: def check_properties(mcs, attributes):
          
          include, exclude = mcs.get_prepared_include_exclude(attributes)
          properties = mcs.get_properties(attributes)
          intersections = list(
              set(properties).intersection(include if include else exclude))
          if not intersections:
              return None
  
          attr_name = '__include__' if include else '__exclude__'
  
          raise AttributeError(
              "It is not allowed to mention already defined properties: "
              "{0} in {1} attributes.".format(", ".join(intersections),
                                              attr_name))
docs: Check whether intersections exist.
  
          :type attributes: dict