code: public MultipleDataProviderContext<DPO> read(DataProvider<DPO> dataProvider) {
          if (dataProvider != null) {
              addedDataProviders.add(dataProvider);
          }
  
          // Change context
          return new MultipleDataProviderContext<DPO>(addedTriggers, addedDataProviders);
      }
docs: Adds the specified data provider to the validator under construction.
  
  @param dataProvider Data provider to be added.
  
  @return Context allowing further construction of the validator using the DSL.