eval.c:3787
static VALUE
rb_mod_private_method_defined(mod, mid)
    VALUE mod, mid;
{
    ID id = rb_to_id(mid);
    int noex;

    if (rb_get_method_body(&mod, &id, &noex)) {
	if (VISI_CHECK(noex, NOEX_PRIVATE))
	    return Qtrue;
    }
    return Qfalse;
}
