code: def authTryNextMethod(self):
          
          if not self.authOrder:
              raise DBusAuthenticationFailed()
          
          self.authMech  = self.authOrder.pop()
              
          if self.authMech == 'DBUS_COOKIE_SHA1':
              self.sendAuthMessage('AUTH ' + self.authMech + ' ' +
                                   hexlify(getpass.getuser()))
          elif self.authMech == 'ANONYMOUS':
              self.sendAuthMessage('AUTH ' + self.authMech + ' ' +
                                   hexlify("txdbus"))
          else:
              self.sendAuthMessage('AUTH ' + self.authMech)
docs: Tries the next authentication method or raises a failure if all mechanisms
          have been tried.