public function testRandomNumber()
{
$this->specify("number does not generated correct length of number", function () {
$lens = [2, 100, 9, 8777, 123456789, 1, 9999999999999];
$random = new Random();
foreach ($lens as $len) {
$actual = $random->number($len);
expect($actual)->lessOrEquals($len);
expect($actual)->greaterOrEquals(0);
}
});
}