src/Assistant.php
public function add(string $key)
    {
        foreach ($this->items as  &$items) {
            array_push($items, $key);
        }

        return $this;
    }
public function add(string $key)
    {
        foreach ($this->items as  &$items) {
            array_push($items, $key);
        }

        return $this;
    }
Add cached key.

@param string $key 缓存的key

@return static