code: public Map<String, TreeItemIdNode> getCustomIdNodeMap() {
  		// No user context present
  		if (getScratchMap() == null) {
  			return createCustomIdNodeMapping();
  		}
  		Map<String, TreeItemIdNode> map = (Map<String, TreeItemIdNode>) getScratchMap().get(CUSTOM_IDS_TO_NODE_SCRATCH_MAP_KEY);
  		if (map == null) {
  			map = createCustomIdNodeMapping();
  			getScratchMap().put(CUSTOM_IDS_TO_NODE_SCRATCH_MAP_KEY, map);
  		}
  		return map;
  	}
docs: Map an item id to its node in the custom tree. As this can be expensive save the map onto the scratch pad.
  
  @return the map between the custom item ids and their node item.