/**
  * Returns the subFolder element matching the supplied folder name.
  *
  * @param folderName the name of the subFolder to find.
  * @return the subFolder element if found {@code null} otherwise.
  */
 public BluetoothMapFolderElement getSubFolder(String folderName) {
   for (BluetoothMapFolderElement subFolder : subFolders) {
     if (subFolder.getName().equals(folderName)) return subFolder;
   }
   return null;
 }