Unset operations are not seen as changing a value

[AJenbo]

    function test()
    {
        $userHelper = [1,2];
        unset($options[0]);
    }

Refactoring the secound line in the function will fail to take account for the unsetting changing $options and it needing to be retuned or passed by reference.

    function test()
    {
        $options = [1,2];
        $this->asd($options);
    }

    private function asd($options)
    {
        unset($options[0]);
    }

expected

    function test()
    {
        $options = [1,2];
        $options = $this->asd($options);
    }

    private function asd($options)
    {
        unset($options[0]);
        return $options;
    }