This function works like g_object_set_qdata(), but in addition,
a void (*destroy) (gpointer) function may be specified which is
called with data as argument when the object is finalized, or
the data is being overwritten by a call to g_object_set_qdata()
with the same quark.
This function works like g_object_set_qdata(), but in addition, a void (*destroy) (gpointer) function may be specified which is called with data as argument when the object is finalized, or the data is being overwritten by a call to g_object_set_qdata() with the same quark.