code: private boolean isParent(ItemData data, ItemData parent)
     {
        String id1 = data.getParentIdentifier();
        String id2 = parent.getIdentifier();
        if (id1 == id2) // NOSONAR 
           return true;
        if (id1 == null && id2 != null)
           return false;
        return id1 != null && id1.equals(id2);
     }
docs: Check if item <b>parent</b> is parent item of item <b>data</b>.
  
  @param data - Possible child ItemData.
  @param parent - Possible parent ItemData.
  @return True if parent of both ItemData the same.