@Nullable
  private static VirtualFile getHelpFile(AntDomElement antElement, final VirtualFile documentationRoot) {
    final XmlTag xmlTag = antElement.getXmlTag();
    if (xmlTag == null) {
      return null;
    }
    @NonNls final String helpFileShortName = "/" + xmlTag.getName() + ".html";

    for (String folderName : DOC_FOLDER_NAMES) {
      final VirtualFile candidateHelpFile = documentationRoot.findFileByRelativePath(folderName + helpFileShortName);
      if (candidateHelpFile != null) {
        return candidateHelpFile;
      }
    }

    if(antElement instanceof AntDomTarget|| antElement instanceof AntDomProject) {
      final VirtualFile candidateHelpFile = documentationRoot.findFileByRelativePath("using.html");
      if (candidateHelpFile != null) {
        return candidateHelpFile;
      }
    }

    return null;
  }
@Nullable
  private static VirtualFile getHelpFile(AntDomElement antElement, final VirtualFile documentationRoot)