code: @Override
      public void handleDeployFailed(Vertx vertx, String mainVerticle, DeploymentOptions deploymentOptions, Throwable cause) {
        // Default behaviour is to close Vert.x if the deploy failed
        vertx.close();
      }
docs: A deployment failure has been encountered. You can override this method to customize the behavior.
  By default it closes the `vertx` instance.
  
  @param vertx             the vert.x instance
  @param mainVerticle      the verticle
  @param deploymentOptions the verticle deployment options
  @param cause             the cause of the failure