@Override
    protected boolean precheck(VirtualFile beforeFile, VirtualFile afterFile, DelayedPrecheckContext context) {
      if (beforeFile == null) {
        setErrorMessage(fileNotFoundMessage(myBeforeName));
      }
      return beforeFile != null;
    }
@Override
    protected boolean precheck(VirtualFile beforeFile, VirtualFile afterFile, DelayedPrecheckContext context)