code: public void sample(final Function<T, double[]> function) {
  		_params.values()
  			.subSeq(_dataSet.nextParamIndex())
  			.forEach(p -> _dataSet.add(function.apply(p)));
  	}
docs: Calculates the test values for all parameters. The length of the
  resulting {@code double[]} array must be {@link #dataSize()}.
  
  @param function the test function