code: private DirectoryEntry getNormalizedParent( DirectoryEntry parent )
      {
          if ( parent.getParent() == null )
          {
              return getRoot();
          }
          else
          {
              return mkdir( parent.getParent(), parent.getName() );
          }
      }
docs: Gets the parent directory entry (ensuring it exists).
  
  @param parent the parent entry to get.
  @return the actual directory entry instance used as the key in {@link #contents}.
  @since 1.0