code: private void doMultiMapRemove(final Message<JsonObject> message) {
      final String name = message.body().getString("name");
      if (name == null) {
        message.reply(new JsonObject().putString("status", "error").putString("message", "No name specified."));
        return;
      }
  
      final Object key = message.body().getValue("key");
      if (key == null) {
        message.reply(new JsonObject().putString("status", "error").putString("message", "No key specified."));
        return;
      }
  
      final Object value = message.body().getValue("value");
      if (value != null) {
        context.execute(new Action<Boolean>() {
          @Override
          public Boolean perform() {
            return data.getMultiMap(formatKey(name)).remove(key, value);
          }
        }, new Handler<AsyncResult<Boolean>>() {
          @Override
          public void handle(AsyncResult<Boolean> result) {
            if (result.failed()) {
              message.reply(new JsonObject().putString("status", "error").putString("message", result.cause().getMessage()));
            } else {
              message.reply(new JsonObject().putString("status", "ok").putBoolean("result", result.result()));
            }
          }
        });
      } else {
        context.execute(new Action<Collection<Object>>() {
          @Override
          public Collection<Object> perform() {
            return data.getMultiMap(formatKey(name)).remove(key);
          }
        }, new Handler<AsyncResult<Collection<Object>>>() {
          @Override
          public void handle(AsyncResult<Collection<Object>> result) {
            if (result.failed()) {
              message.reply(new JsonObject().putString("status", "error").putString("message", result.cause().getMessage()));
            } else {
              message.reply(new JsonObject().putString("status", "ok").putArray("result", new JsonArray(result.result().toArray(new Object[result.result().size()]))));
            }
          }
        });
      }
    }
docs: Handles a cluster multi-map remove command.