code: def runAndWait(self):
          
          if self._inLoop:
              raise RuntimeError('run loop already started')
          self._inLoop = True
          self._driverLoop = True
          self.proxy.runAndWait()
docs: Runs an event loop until all commands queued up until this method call
          complete. Blocks during the event loop and returns when the queue is
          cleared.
  
          @raise RuntimeError: When the loop is already running