code: def is_subtype_of(self, type_name, context=None):
          
          if self.qname() == type_name:
              return True
          for anc in self.ancestors(context=context):
              if anc.qname() == type_name:
                  return True
          return False
docs: Whether this class is a subtype of the given type.
  
          :param type_name: The name of the type of check against.
          :type type_name: str
  
          :returns: True if this class is a subtype of the given type,
              False otherwise.
          :rtype: bool