@Override
    public void visitPyStringLiteralExpression(final @NotNull PyStringLiteralExpression string) {
      String stringText = string.getText();
      int length = PyStringLiteralUtil.getPrefixLength(stringText);
      stringText = stringText.substring(length);
      final PyDocStringOwner docStringOwner = PsiTreeUtil.getParentOfType(string, PyDocStringOwner.class);
      if (docStringOwner != null) {
        if (docStringOwner.getDocStringExpression() == string)  {
          if (!stringText.startsWith("\"\"\"") && !stringText.endsWith("\"\"\"")) {
            ProblemsHolder holder = getHolder();
            if (holder != null) {
              int quoteCount = 1;
              if (stringText.startsWith("'''") && stringText.endsWith("'''")) {
                quoteCount = 3;
              }
              TextRange trStart = new TextRange(length, length+quoteCount);
              TextRange trEnd = new TextRange(stringText.length()+length-quoteCount,
                                              stringText.length()+length);
              if (string.getStringValue().isEmpty())
                holder.registerProblem(string, PyPsiBundle.message("INSP.message.single.quoted.docstring"),
                                       new ConvertDocstringQuickFix());
              else {
                holder.registerProblem(string, trStart,
                                       PyPsiBundle.message("INSP.message.single.quoted.docstring"), new ConvertDocstringQuickFix());
                holder.registerProblem(string, trEnd,
                                       PyPsiBundle.message("INSP.message.single.quoted.docstring"), new ConvertDocstringQuickFix());
              }
            }
          }
        }
      }
    }
@Override
    public void visitPyStringLiteralExpression(final @NotNull PyStringLiteralExpression string)