code: def get_xml(self, fp, format=FORMAT_NATIVE):
          
          r = self._client.request('GET', getattr(self, format), stream=True)
          filename = stream.stream_response_to_file(r, path=fp)
          return filename
docs: Returns the XML metadata for this source, converted to the requested format.
          Converted metadata may not contain all the same information as the native format.
  
          :param file fp: A path, or an open file-like object which the content should be written to.
          :param str format: desired format for the output. This should be one of the available
              formats from :py:meth:`.get_formats`, or :py:attr:`.FORMAT_NATIVE` for the native format.
  
          If you pass this function an open file-like object as the fp parameter, the function will
          not close that file for you.