@Override
  public void visitLiteralExpression(@NotNull PsiLiteralExpression expression) {
    super.visitLiteralExpression(expression);

    if (!hasErrorResults() &&
        expression.getParent() instanceof PsiCaseLabelElementList &&
        expression.textMatches(PsiKeyword.NULL)) {
      add(checkFeature(expression, JavaFeature.PATTERNS_IN_SWITCH));
    }

    if (!hasErrorResults()) HighlightUtil.checkIllegalUnicodeEscapes(expression, myErrorSink);
    if (!hasErrorResults()) {
      add(HighlightUtil.checkLiteralExpressionParsingError(expression, myLanguageLevel, myFile, null));
    }
  }
@Override
  public void visitLiteralExpression(@NotNull PsiLiteralExpression expression)