code: def parse_response(self, response):
          
          result = {}
          root = etree.fromstring(response)
          for argument in self.arguments.values():
              try:
                  value = root.find('.//%s' % argument.name).text
              except AttributeError:
                  # will happen by searching for in-parameters and by
                  # parsing responses with status_code != 200
                  continue
              if argument.data_type.startswith('ui'):
                  try:
                      value = int(value)
                  except ValueError:
                      # should not happen
                      value = None
              result[argument.name] = value
          return result
docs: Evaluates the action-call response from a FritzBox.
          The response is a xml byte-string.
          Returns a dictionary with the received arguments-value pairs.
          The values are converted according to the given data_types.
          TODO: boolean and signed integers data-types from tr64 responses