docs: def serialize_to_transport(self, doc_format="xml", *args, **kwargs):
          """Serialize ResourceMap to UTF-8 encoded XML document.
  
          Args:
            doc_format: str
              One of: ``xml``, ``n3``, ``turtle``, ``nt``, ``pretty-xml``, ``trix``,
              ``trig`` and ``nquads``.
  
            args and kwargs:
              Optional arguments forwarded to rdflib.ConjunctiveGraph.serialize().
  
          Returns:
            bytes: UTF-8 encoded XML doc.
  
          Note:
            Only the default, "xml", is automatically indexed by DataONE.
  
          """
          return super(ResourceMap, self).serialize(
              format=doc_format, encoding="utf-8", *args, **kwargs
          )