public function play($url = null, $attributes = array()) {
        return $this->nest(new Voice\Play($url, $attributes));
    }
public function play($url = null, $attributes = array()) {
        return $this->nest(new Voice\Play($url, $attributes));
    }
public function play ( $ url = null , $ attributes = array ( ) ) { return $ this -> nest ( new Voice \ Play ( $ url , $ attributes ) ) ; }
Add Play child.

@param url $url Media URL
@param array $attributes Optional attributes
@return TwiML Child element.
Add Play child .