eval.c:6138
static void
set_method_visibility(self, argc, argv, ex)
    VALUE self;
    int argc;
    VALUE *argv;
    ID ex;
{
    int i;

    secure_visibility(self);
    for (i=0; i<argc; i++) {
	rb_export_method(self, rb_to_id(argv[i]), ex);
    }
    rb_clear_cache_by_class(self);
}
