Deserialize a file filter from an a{sv} variant in the format produced by gtk_file_filter_to_gvariant().
an a{sv} #GVariant
Return: a new #GtkFileFilter object
ConstructionException GTK+ fails to create the object.
3.22
See Implementation
Deserialize a file filter from an a{sv} variant in the format produced by gtk_file_filter_to_gvariant().