docs: def answer (self, headers, **options):
          """
          Places a call or sends an an IM, Twitter, or SMS message. To start a call, use the Session API headers tell Tropo headers launch your code.
          Arguments: headers is a String.
          Argument: **options is a set of optional keyword arguments.
          See https://www.tropo.com/docs/webapi/answer
          """
          self._steps.append(Answer (headers, **options).obj)