code: def annotate_proto(self, text, annotators=None):
          
          properties = {
              'annotators': ','.join(annotators or self.default_annotators),
              'outputFormat': 'serialized',
              'serializer': 'edu.stanford.nlp.pipeline.ProtobufAnnotationSerializer'
          }
          r = self._request(text, properties)
          buffer = r.content  # bytes
  
          size, pos = _DecodeVarint(buffer, 0)
          buffer = buffer[pos:(pos + size)]
          doc = CoreNLP_pb2.Document()
          doc.ParseFromString(buffer)
          return doc
docs: Return a Document protocol buffer from the CoreNLP server, containing annotations of the text.
  
          :param (str) text: text to be annotated
          :param (list[str]) annotators: a list of annotator names
  
          :return (CoreNLP_pb2.Document): a Document protocol buffer