code: def valid_content_type(self, content_type, accept):
          
          accept_tokens = accept.replace(' ', '').split(';')
          content_type_tokens = content_type.replace(' ', '').split(';')
  
          return (
              all(elem in content_type_tokens for elem in accept_tokens) and
              (content_type_tokens[0] == 'application/vnd.oasis.taxii+json' or
               content_type_tokens[0] == 'application/vnd.oasis.stix+json')
          )
docs: Check that the server is returning a valid Content-Type
  
          Args:
              content_type (str): ``Content-Type:`` header value
              accept (str): media type to include in the ``Accept:`` header.