MailThief\Support\MailThiefCollection::contains PHP Метод

    public function contains($key, $value = null)
    {
        if (func_num_args() == 2) {
            return $this->contains(function ($item) use($key, $value) {
                return data_get($item, $key) == $value;
            });
        }
        if ($this->useAsCallable($key)) {
            return !is_null($this->first($key));
        }
        return in_array($key, $this->items);
    }