This function is essentially the same as g_type_class_ref(), except that
the classes reference count isn't incremented. As a consequence, this function
may return NULL if the class of the type passed in does not currently
exist (hasn't been referenced before).
This function is essentially the same as g_type_class_ref(), except that the classes reference count isn't incremented. As a consequence, this function may return NULL if the class of the type passed in does not currently exist (hasn't been referenced before).