docs: public static DirectoryEntry equivalent( FileSystem target, DirectoryEntry directory )
      {
          if ( target.equals( directory.getFileSystem() ) )
          {
              return directory;
          }
          if ( directory.getParent() == null )
          {
              return target.getRoot();
          }
          return new DefaultDirectoryEntry( target, equivalent( target, directory.getParent() ), directory.getName() );
      }