
  [;1m-spec change_group(Filename, Gid) -> ok | {error, Reason}[0m
  [;1m                      when[0m
  [;1m                          Filename :: name_all(),[0m
  [;1m                          Gid :: integer(),[0m
  [;1m                          Reason :: posix() | badarg.[0m

  Changes group of a file. See [;;4mwrite_file_info/2[0m.
