public function relation($name, $label, $builder = null)
    {
        if (is_null($builder)) {
            $builder = $label;
            $label = '';
        }

        return $this->addRelation($name, $builder, $label);
    }
public function relation($name, $label, $builder = null)
    {
        if (is_null($builder)) {
            $builder = $label;
            $label = '';
        }

        return $this->addRelation($name, $builder, $label);
    }
public function relation ( $ name , $ label , $ builder = null ) { if ( is_null ( $ builder ) ) { $ builder = $ label ; $ label = '' ; } return $ this -> addRelation ( $ name , $ builder , $ label ) ; }
Add a relation to show.

@param string          $name
@param string|\Closure $label
@param null|\Closure   $builder

@return Relation
Add a relation to show .