code: private void doInternalUndeploy(final Message<JsonObject> message) {
      String type = message.body().getString("type");
      if (type == null) {
        message.reply(new JsonObject().putString("status", "error").putString("message", "No deployment type specified."));
      } else {
        switch (type) {
          case "module":
            doInternalUndeployModule(message);
            break;
          case "verticle":
            doInternalUndeployVerticle(message);
            break;
          default:
            message.reply(new JsonObject().putString("status", "error").putString("message", "Invalid deployment type " + type));
            break;
        }
      }
    }
docs: Internally undeploys a module/verticle.