Deserialize a file filter from a GVariant.
The variant must be in the format produced by [method@Gtk.FileFilter.to_gvariant].
an a{sv} GVariant
a new GtkFileFilter object
ConstructionException GTK+ fails to create the object.
See Implementation
Deserialize a file filter from a GVariant.
The variant must be in the format produced by [method@Gtk.FileFilter.to_gvariant].