docs: def _get_params(self):
          """
          Generate SOAP parameters.
          """
          
          params = {'accountNumber': self._service.accountNumber}
          
          # Include object variables that are in field_order
          for key, val in self.__dict__.iteritems():
              if key in self.field_order:
                  
                  # Turn into Unicode
                  if isinstance(val, str,):
                      val = val.decode('utf8')
                  
                  params[key] = val
          
          # Set missing parameters as empty strings
          for key in self.field_order:
              if key not in params:
                  params[key] = u''
          
          # Parameter sorting method
          def order_keys(k):
              if k[0] in self.field_order:
                  return self.field_order.index(k[0])
              return len(self.field_order) + 1
          
          # Sort the ordered dictionary
          params = OrderedDict(sorted(params.items(), key=order_keys))
          
          # Add hash to dictionary if present
          if hasattr(self, 'hash') and self.hash is not None:
              params['hash'] = self.hash
          
          return params