code: @SuppressWarnings("unchecked")
      private Map<String, Object> getViewComponentIds()
      {
          Map<Object, Object> attributes = _facesContext.getAttributes();
          Map<String, Object> viewComponentIds;
  
          if (_parent == null)
          {
              // top level _componentInstance
              viewComponentIds = new HashMap<String, Object>();
              attributes.put(VIEW_IDS, viewComponentIds);
          }
          else
          {
              viewComponentIds = (Map<String, Object>) attributes.get(VIEW_IDS);
              
              // Check if null, this can happen if someone programatically tries to do an include of a 
              // JSP fragment. This code will prevent NullPointerException from happening in such cases.
              if (viewComponentIds == null)
              {
                  viewComponentIds = new HashMap<String, Object>();
                  attributes.put(VIEW_IDS, viewComponentIds);
              }
          }
  
          return viewComponentIds;
      }
docs: Map of <ID,Tag> in the view