code: def rdf(self, rdf: Optional[Union[str, Graph]]) -> None:
          
          if isinstance(rdf, Graph):
              self.g = rdf
          else:
              self.g = Graph()
              if isinstance(rdf, str):
                  if '\n' in rdf or '\r' in rdf:
                      self.g.parse(data=rdf, format=self.rdf_format)
                  elif ':' in rdf:
                      self.g.parse(location=rdf, format=self.rdf_format)
                  else:
                      self.g.parse(source=rdf, format=self.rdf_format)
docs: Set the RDF DataSet to be evaulated.  If ``rdf`` is a string, the presence of a return is the
          indicator that it is text instead of a location.
  
          :param rdf: File name, URL, representation of rdflib Graph