+ * the synchronization is always from the source to the target.
+ * @G_BINDING_INVERT_BOOLEAN: If the two properties being bound are
+ * booleans, setting one to %TRUE will result in the other being
+ * set to %FALSE and vice versa. This flag will only work for
+ * boolean properties, and cannot be used when passing custom
+ * transformation functions to g_object_bind_property_full().