code: @Provides
  	List<? extends DataSource> provideContainerChildDataSources(final Configuration configuration, final Map<String, DataSource> availableDataSources) {
  
  		List<DataSource> dataSources = newArrayListWithExpectedSize(3);
  		String key = "dataSource.container.dsref";
  
  		for (int i = 1;; ++i) {
  			String dsKey = key + i;
  			String dsName = configuration.get(dsKey);
  			if (dsName == null) {
  				break;
  			}
  			DataSource ds = availableDataSources.get(dsName);
  			if (ds == null) {
  				throw new ProvisionException("DataSource with name '" + dsName + "' not available. Check your configuration.");
  			}
  			dataSources.add(ds);
  		}
  
  		return dataSources;
  	}
docs: Reads child datasources for the ContainerDataSource from the configuration.