CustomSorter

Description:

[ CCode ( has_construct_function = false ) ]
public CustomSorter (owned CompareDataFunc? sort_func)

Creates a new `GtkSorter` that works by calling sort_func to compare items.

If sort_func is null, all items are considered equal.

sort_func	the `GCompareDataFunc` to use for sorting
user_data	user data to pass to `sort_func`
user_destroy	destroy notify for `user_data`

a new `GtkCustomSorter`