public function testEqualProbability()
{
$generator = new FrequencyGenerator([[1, 42], [1, 21]]);
$countOf = $this->distribute($generator);
$this->assertTrue(abs($countOf[42] - $countOf[21]) < 100, 'Generators have the same frequency but one is chosen more often than the other: ' . var_export($countOf, true));
}