@ResponseBody
	@ExceptionHandler
	@ResponseStatus(HttpStatus.NOT_FOUND)
	public VndErrors onNoSuchMetricException(NoSuchMetricException e) {
		String logref = logDebug(e);
		return new VndErrors(logref, e.getMessage());
	}
Handles the case where client tried to deploy something that is has an invalid definition.
spring-xd-dirt/src/main/java/org/springframework/xd/dirt/rest/RestControllerAdvice.java