public function testL1NormWithZeroSumCondition()
{
$samples = [[0, 0, 0], [2, 0, 0], [0, 1, -1]];
$normalized = [[0.33, 0.33, 0.33], [1.0, 0.0, 0.0], [0.0, 0.5, -0.5]];
$normalizer = new Normalizer(Normalizer::NORM_L1);
$normalizer->transform($samples);
$this->assertEquals($normalized, $samples, '', $delta = 0.01);
}