code: public void addValidation(Object key, Validation validation){
          initMapOnce();
          validations.put(key, validation);
          // update aggregated value
          passedAll = passedAll && validation.passed();
      }
docs: Add a validation object. A key is required that can be used to retrieve the validation object.
  
  @param key key used to retrieve the validation object
  @param validation validation object