code: def get_client(self, request=None):
          
  
          if not isinstance(request, oauth.Request):
              request = self.get_oauth_request()
          client_key = request.get_parameter('oauth_consumer_key')
          if not client_key:
              raise Exception('Missing "oauth_consumer_key" parameter in ' \
                  'OAuth "Authorization" header')
  
          client = models.Client.get_by_key_name(client_key)
          if not client:
              raise Exception('Client "%s" not found.' % client_key)
  
          return client
docs: Return the client from the OAuth parameters.