protected static Document createXPathDocument(Project project, HistoryElement historyElement) {

        final String expression = historyElement != null ? historyElement.expression : "";
        final PsiFile file = PsiFileFactory.getInstance(project).createFileFromText("DummyFile.xpath", XPathFileType.XPATH, expression, LocalTimeCounter.currentTime(), true);
        final Document document = PsiDocumentManager.getInstance(project).getDocument(file);
        // not sure why this is required...
        assert document != null;
        document.setReadOnly(false);

        assert document.isWritable() : "WTF, document is not writable? Text = <" + expression + ">";
        return document;
    }
protected static Document createXPathDocument(Project project, HistoryElement historyElement)