src/Sonic/Extension/Twig.php
public function link_for($file_name)
    {
        $sonic = \Sonic\Sonic::instance();
        return $sonic->app['helper']->link_for($file_name);
    }
public function link_for($file_name)
    {
        $sonic = \Sonic\Sonic::instance();
        return $sonic->app['helper']->link_for($file_name);
    }
Returns a HTML <a> for a given filename in the 'content' directory

@see    \Sonic\Helper::link_for()
@param  string $file_name
@return string|null
@codeCoverageIgnore