static <A> AutoCloseable mapMethodLike vmBus_onMessage(fS msg, final VF1<A> onMessage) {
  Map<S, Set> map = vm_busListenersByMessage_live();
  synchronized(map) {
    Set listeners = map.get(msg);
    if (listeners == null) map.put(msg, listeners = syncIdentityHashSet());
    // We're technically violating the one-synchronized-object-per-thread rule,
    // but it should be OK here.
    // TODO: remove empty sets from map
    ret tempAdd(listeners, voidfunc(S _msg, O arg) {
      callF(onMessage, arg)
    });
  }
}

ifclass VF2
static <A, B> AutoCloseable vmBus_onMessage(S msg, final VF2<A, B> onMessage) {
  ret vmBus_onMessage(msg, voidfunc(O[] o) {
    callF(onMessage, first(o), second(o));
  });
}
endif

static <A, B> AutoCloseable vmBus_onMessage(S msg, final IVF2<A, B> onMessage) {
  ret vmBus_onMessage(msg, voidfunc(O[] o) {
    callF(onMessage, first(o), second(o));
  });
}

ifclass VF3
static <A, B, C> AutoCloseable vmBus_onMessage(S msg, final VF3<A, B, C> onMessage) {
  ret vmBus_onMessage(msg, voidfunc(O[] o) {
    callF(onMessage, first(o), second(o), third(o));
  });
}
endif

ifclass VF4
static <A, B, C, D> AutoCloseable vmBus_onMessage(S msg, VF4<A, B, C, D> onMessage) {
  ret vmBus_onMessage(msg, voidfunc(O[] o) {
    callF(onMessage, first(o), second(o), third(o), last(o));
  });
}
endif

static AutoCloseable vmBus_onMessage(S msg, Runnable onMessage) {
  ret vmBus_onMessage(msg, runnableToVF1(onMessage));
}

Began life as a copy of #1017923