Gets the file that section was parsed from.
If no such file exists, for example because the CSS was loaded via gtk.css_provider.CssProvider.loadFromData, then NULL is returned.
the gio.file.File from which the section was parsed
Gets the file that section was parsed from.
If no such file exists, for example because the CSS was loaded via gtk.css_provider.CssProvider.loadFromData, then NULL is returned.