code: public static Constraint max(final Number max) {
  		return new Constraint("max", maxPayload(max)) {
  			public boolean isValid(Object actualValue) {
  				return actualValue == null || (actualValue instanceof Number && max != null &&
  						max.longValue() >= ((Number) actualValue).longValue());
  			}
  		};
  	}
docs: The 'max' constraint - field must contain a number smaller than or equal to max.
  @param max the maximum value
  @return constraint