'Places a call or sends an an IM, Twitter, or SMS message. To start a call, use the Session API to tell Tropo to launch your code.
Arguments: to is a String.
Argument: **options is a set of optional keyword arguments.
See https://www.tropo.com/docs/webapi/call.htm'

def call(self, to, **options):

    self._steps.append(Call(to, **options).obj)
