code: public <RO> SingleRuleContext<DPO, Collection<DPO>, RO> check(Collection<Rule<Collection<DPO>, RO>> rules) {
          List<Rule<Collection<DPO>, RO>> addedRules = new ArrayList<Rule<Collection<DPO>, RO>>();
          if (rules != null) {
              addedRules.addAll(rules);
          }
  
          // Change context
          return new SingleRuleContext<DPO, Collection<DPO>, RO>(addedTriggers, addedDataProviders,
                  GeneralValidator.MappingStrategy.JOIN, null, addedRules);
      }
docs: Adds the specified rules to the validator under construction.
  
  @param rules Rules to be added.
  @param <RO>  Type of rule output.
  
  @return Context allowing further construction of the validator using the DSL.