>>> client.service.GetAppointments(MessageId="asd", SoftwareId="bb", AppointmentQuery=x)
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "/home/am/tg2env/lib/python2.6/site-packages/suds-0.4-py2.6.egg/suds/client.py", line 542, in __call__
    return client.invoke(args, kwargs)
  File "/home/am/tg2env/lib/python2.6/site-packages/suds-0.4-py2.6.egg/suds/client.py", line 603, in invoke
    result = self.send(soapenv)
  File "/home/am/tg2env/lib/python2.6/site-packages/suds-0.4-py2.6.egg/suds/client.py", line 643, in send
    f.write(request)
TypeError: argument 1 must be string or read-only character buffer, not instance