public void visitXmlAttribute(XmlAttribute attribute) {
          if (XsltSupport.isXPathAttribute(attribute)) {
            final PsiFile[] xpathFiles = XsltSupport.getFiles(attribute);
            for (PsiFile xpathFile : xpathFiles) {
              xpathFile.accept(this);
            }
          }
        }
public void visitXmlAttribute(XmlAttribute attribute)