code: def _WriteFileEntry(self, file_entry, data_stream_name, destination_file):
      
      source_file_object = file_entry.GetFileObject(
          data_stream_name=data_stream_name)
      if not source_file_object:
        return
  
      try:
        with open(destination_file, 'wb') as destination_file_object:
          source_file_object.seek(0, os.SEEK_SET)
  
          data = source_file_object.read(self._COPY_BUFFER_SIZE)
          while data:
            destination_file_object.write(data)
            data = source_file_object.read(self._COPY_BUFFER_SIZE)
  
      finally:
        source_file_object.close()
docs: Writes the contents of the source file entry to a destination file.
  
      Note that this function will overwrite an existing file.
  
      Args:
        file_entry (dfvfs.FileEntry): file entry whose content is to be written.
        data_stream_name (str): name of the data stream whose content is to be
            written.
        destination_file (str): path of the destination file.