code: @Override
  	public boolean hasMoreData(final String dataSetKey) {
  		if (dataSetKeys.isEmpty()) {
  			// Fill set of known data set keys
  			for (String constraintId : getGenerator().getConstraintIds()) {
  				if (constraintId != null && constraintId.endsWith(".all")) {
  					String key = StringUtils.substringBefore(constraintId, "." + GeneratorConstants.ALL_CONSTRAINT);
  					dataSetKeys.add(key);
  				}
  			}
  		}
  		return dataSetKeys.contains(dataSetKey);
  	}
docs: {@inheritDoc}
  
  @return Always returns {@code true} for known data set keys, because new data is generated
  upon request.