code: public Version getRootVersion() throws RepositoryException
     {
        checkValid();
  
        VersionImpl version =
           (VersionImpl)dataManager
              .getItem(nodeData(), new QPathEntry(Constants.JCR_ROOTVERSION, 0), true, ItemType.NODE);
        if (version == null)
        {
           throw new VersionException("There are no root version in the version history " + getPath());
        }
  
        return version;
     }
docs: {@inheritDoc}