ZF\Apigility\Admin\InputFilter\CreateContentNegotiationInputFilter::__construct PHP Method

    public function __construct()
    {
        parent::__construct();
        $this->get('selectors')->setRequired(false);
        $input = new Input('content_name');
        $input->setRequired(true);
        $chain = $input->getValidatorChain();
        $chain->attach(new Validator\IsStringValidator());
        $this->add($input);
    }