public function sub($name, $attrs = null, $ns = null)
    {
        //@TODO: attrs is ignored
        foreach ($this->subs as $sub) {
            if ($sub->name === $name and ($ns === null or $sub->ns === $ns)) {
                return $sub;
            }
        }
        return null;
    }
public function sub($name, $attrs = null, $ns = null)
    {
        //@TODO: attrs is ignored
        foreach ($this->subs as $sub) {
            if ($sub->name === $name and ($ns === null or $sub->ns === $ns)) {
                return $sub;
            }
        }
        return null;
    }
public function sub ( $ name , $ attrs = null , $ ns = null ) { //@TODO: attrs is ignored foreach ( $ this -> subs as $ sub ) { if ( $ sub -> name === $ name and ( $ ns === null or $ sub -> ns === $ ns ) ) { return $ sub ; } } return null ; }
Return a sub

@param string $name
@param string $attrs
@param string $ns
Return a sub