src/Builder.php
public function fit($gravity = null)
    {
        $this->manipulations['c'] = 'fit';

        if (!is_null($gravity)) {
            $this->manipulations['g'] = $gravity;
        }

        return $this;
    }
public function fit($gravity = null)
    {
        $this->manipulations['c'] = 'fit';

        if (!is_null($gravity)) {
            $this->manipulations['g'] = $gravity;
        }

        return $this;
    }
Fit the image when resizing it.

@param null|string $gravity
@return $this