@Test
public void error() {

	final Codec<Tree<Op<Double>, ?>, ProgramGene<Double>> codec =
		Regression.codecOf(OPS, TMS, 5, t -> t.gene().size() < 30);
	final Regression<Double> regression = Regression.of(
		codec,
		Error.of(LossFunction::mse),
		Sample.ofDouble(-1.0, -8.0000),
		Sample.ofDouble(-0.9, -6.2460),
		Sample.ofDouble(-0.8, -4.7680),
		Sample.ofDouble(-0.7, -3.5420),
		Sample.ofDouble(-0.6, -2.5440),
		Sample.ofDouble(-0.5, -1.7500),
		Sample.ofDouble(-0.4, -1.1360),
		Sample.ofDouble(-0.3, -0.6780),
		Sample.ofDouble(-0.2, -0.3520),
		Sample.ofDouble(-0.1, -0.1340),
		Sample.ofDouble(0.0, 0.0000),
		Sample.ofDouble(0.1, 0.0740),
		Sample.ofDouble(0.2, 0.1120),
		Sample.ofDouble(0.3, 0.1380),
		Sample.ofDouble(0.4, 0.1760),
		Sample.ofDouble(0.5, 0.2500),
		Sample.ofDouble(0.6, 0.3840),
		Sample.ofDouble(0.7, 0.6020),
		Sample.ofDouble(0.8, 0.9280),
		Sample.ofDouble(0.9, 1.3860),
		Sample.ofDouble(1.0, 2.0000)
	);
	final Tree<Op<Double>, ?> tree = codec.encoding().newInstance().gene();
	regression.error(tree);
}