src/Primitive/Container/Container.php
public function forget($key)
    {
        Arr::forget($this->items, $this->getStringable($key));

        return $this;
    }
public function forget($key)
    {
        Arr::forget($this->items, $this->getStringable($key));

        return $this;
    }
Remove key from Container. Supports dot notation.

@param mixed $key
@return $this