src/Leevel/Http/Bag.php
public function get(string $key, $defaults = null)
    {
        $key = $this->normalize($key);

        return $this->filter($key, $defaults);
    }
public function get(string $key, $defaults = null)
    {
        $key = $this->normalize($key);

        return $this->filter($key, $defaults);
    }
取回元素值.

@param string $key
@param mixed  $defaults

@return mixed