def ListFileEntries(self, base_path_specs, output_writer):
    """Lists file entries in the base path specification.

    Args:
      base_path_specs (list[dfvfs.PathSpec]): source path specification.
      output_writer (StdoutWriter): output writer.
    """
    for base_path_spec in base_path_specs:
      file_system = resolver.Resolver.OpenFileSystem(base_path_spec)
      file_entry = resolver.Resolver.OpenFileEntry(base_path_spec)
      if file_entry is None:
        logging.warning(
            'Unable to open base path specification:\n{0:s}'.format(
                base_path_spec.comparable))
        return

      self._ListFileEntry(file_system, file_entry, '', output_writer)
Lists file entries in the base path specification.

    Args:
      base_path_specs (list[dfvfs.PathSpec]): source path specification.
      output_writer (StdoutWriter): output writer.