pub unsafe extern "C" fn g_tree_new_full(
    key_compare_func: Option<unsafe extern "C" fn(_: *const c_void, _: *const c_void, _: *mut c_void) -> i32>,
    key_compare_data: *mut c_void,
    key_destroy_func: Option<unsafe extern "C" fn(_: *mut c_void)>,
    value_destroy_func: Option<unsafe extern "C" fn(_: *mut c_void)>
) -> *mut GTree