code: public static void isFalse(Boolean expression, String constraint) {
  		if(!validation) return;
  		notNull(expression);
  		notNull(constraint);
  		if(!expression)
  			throw new ParameterException(ErrorCode.CONSTRAINT, "Parameter must not fulfill constraint \""+constraint+"\"");
  	}
docs: Checks if the given boolean expression evaluates to <code>false</code>.
  @param expression The expression to evaluate.
  @param constraint Textual description of the expression to include in the exception in case the validation fails.
  @throws ParameterException if the given expression does not evaluate to <code>false</code>.