Eris\Generator\SequenceGenerator::shrinkInSize PHP Method

    private function shrinkInSize($sequence)
    {
        if (count($sequence->unbox()) === 0) {
            return $sequence;
        }
        $input = $sequence->input();
        $indexOfElementToRemove = array_rand($input);
        unset($input[$indexOfElementToRemove]);
        $input = array_values($input);
        return GeneratedValue::fromValueAndInput(array_map(function ($element) {
            return $element->unbox();
        }, $input), $input, 'sequence');
    }