code: def emit(self, span_datas):
          
  
          try:
  
              # TODO: keep the stream alive.
              # The stream is terminated after iteration completes.
              # To keep it alive, we can enqueue proto spans here
              # and asyncronously read them and send to the agent.
              responses = self.client.Export(
                  self.generate_span_requests(span_datas))
  
              # read response
              for _ in responses:
                  pass
  
          except grpc.RpcError:
              pass
docs: :type span_datas: list of :class:
              `~opencensus.trace.span_data.SpanData`
          :param list of opencensus.trace.span_data.SpanData span_datas:
              SpanData tuples to emit