@Nullable
  private static PsiExpression getNewStringBuffer(PsiExpression expression) {
    expression = PsiUtil.skipParenthesizedExprDown(expression);
    if (expression == null) {
      return null;
    }
    else if (expression instanceof PsiNewExpression || ExpressionUtils.isNullLiteral(expression)) {
      return expression;
    }
    else if (expression instanceof PsiMethodCallExpression) {
      final PsiReferenceExpression methodExpression = ((PsiMethodCallExpression)expression).getMethodExpression();
      @NonNls final String methodName = methodExpression.getReferenceName();
      if ("append".equals(methodName) || "appendCodePoint".equals(methodName) || "insert".equals(methodName)) {
        return getNewStringBuffer(methodExpression.getQualifierExpression());
      }
    }
    return null;
  }
@Nullable
  private static PsiExpression getNewStringBuffer(PsiExpression expression)