Send a voice call to the target phone_number.

        See https://developer.telesign.com/docs/voice-api for detailed API documentation.

def call(self, phone_number, message, message_type, **params):
        """
        Send a voice call to the target phone_number.

        See https://developer.telesign.com/docs/voice-api for detailed API documentation.
        """
        return self.post(VOICE_RESOURCE,
                         phone_number=phone_number,
                         message=message,
                         message_type=message_type,
                         **params)