code: public ValidationConfigType<T> constraintMapping(String ... values)
     {
        if (values != null)
        {
           for(String name: values)
           {
              childNode.createChild("constraint-mapping").text(name);
           }
        }
        return this;
     }
docs: Creates for all String objects representing <code>constraint-mapping</code> elements,
  a new <code>constraint-mapping</code> element
  @param values list of <code>constraint-mapping</code> objects
  @return the current instance of <code>ValidationConfigType<T></code>