file_info
Description:
A [class@Gio.
FileInfo] containing the information found in the gzip header of the data stream processed.
This will be `NULL` if the header was not yet fully processed, is not present at all, or the compressor’s [ property@Gio.ZlibDecompressor:format] property is not [enum@Gio.ZlibCompressorFormat.GZIP].