def _get_segment(self, start, size):
    if size == 0:
      return ''
    end = start + size - 1
    self.downloader.GetRange(start, end)
    value = self.download_stream.getvalue()
    # Clear the StringIO object after we've read its contents.
    self.download_stream.truncate(0)
    assert len(value) == size
    return value
Get the given segment of the current GCS file.
dataset/ETHPy150Open GoogleCloudPlatform/DataflowPythonSDK/google/cloud/dataflow/io/gcsio.py/GcsBufferedReader._get_segment