+IMPLEMENT_LISTENER (Engraver_group, override);
+void
+Engraver_group::override (SCM sev)
+{
+ Stream_event *ev = unsmob_stream_event (sev);
+
+ sloppy_general_pushpop_property (context (),
+ ev->get_property ("symbol"),
+ ev->get_property ("property-path"),
+ ev->get_property ("value"));
+}
+
+IMPLEMENT_LISTENER (Engraver_group, revert);
+void
+Engraver_group::revert (SCM sev)
+{
+ Stream_event *ev = unsmob_stream_event (sev);
+
+ sloppy_general_pushpop_property (context (),
+ ev->get_property ("symbol"),
+ ev->get_property ("property-path"),
+ SCM_UNDEFINED);
+}