default Result<T> eval(final Function<? super T[], ? extends T> function) {
		throw new UnsupportedOperationException();
	}
Evaluates the given {@code function} tree with its sample points. The
returned result object may be {@code null} if no sample point has been
added to the <em>sampling</em> when calling the {@code eval} method.

@param function the function to evaluate
@return the evaluated sample result. May be {@code null} if the sampling
        is empty and contains no sample points.
jenetics.prog/src/main/java/io/jenetics/prog/regression/Sampling.java