@Override
  protected void invoke(@NotNull ActionContext context, @NotNull PsiAssignmentExpression assignmentExpression, @NotNull ModPsiUpdater updater) {
    final PsiExpression appendExpression =
      ChangeToAppendUtil.buildAppendExpression(assignmentExpression.getLExpression(), assignmentExpression.getRExpression());
    if (appendExpression == null) return;
    assignmentExpression.replace(appendExpression);
  }
@Override
  protected void invoke(@NotNull ActionContext context, @NotNull PsiAssignmentExpression assignmentExpression, @NotNull ModPsiUpdater updater)