def attach(self, filename=None, content=None, mimetype=None):
        if isinstance(filename, MIMEBase):
            assert content == mimetype == None
            self.attachments.append(filename)
        else:
            assert content is not None
            self.attachments.append((filename, content, mimetype))
:param request: for super
dataset/ETHPy150Open AppScale/appscale/AppServer/lib/django-1.5/django/core/mail/message.py/EmailMessage.attach--crossover with--dataset/ETHPy150Open pika/pika/tests/acceptance/forward_server.py/_TCPHandler.__init__