protected boolean isAttributeContext(PsiElement context) {
    if (context instanceof XmlAttribute
        || (context instanceof XmlToken && ((XmlToken)context).getTokenType() == XmlTokenType.XML_TAG_END)) {
      return true;
    }

    if (context instanceof PsiWhiteSpace) {
      PsiElement prevSibling = context.getPrevSibling();
      if (prevSibling instanceof XmlAttribute) {
        return true;
      }
    }

    return false;
  }
protected boolean isAttributeContext(PsiElement context)