'Add a new <Play> element
:param url: url to play
:param loop: times to loop
:param digits: play DTMF tones during a call
:param kwargs: additional attributes
:return: <Response> element'

def play(self, url=None, loop=None, digits=None, **kwargs):

    return self.nest(Play(url=url, loop=loop, digits=digits, **kwargs))
