def METHOD_NAME(self, chunk_start):
    if chunk_start + self.chunk_size > self.file_end:
        chunk_end = self.file_end
    else:
        chunk_end = chunk_start + self.chunk_size
    chunk_data = self._download_chunk(chunk_start, chunk_end).content
    length = chunk_end - chunk_start
    if length > 0:
        self._write_to_stream(chunk_data, chunk_start)
        self._update_progress(length)