code: def fill_childgoid2obj(childgoid2obj, parent_obj):
      
      for child_obj in parent_obj.children:
          if child_obj.id not in childgoid2obj:
              childgoid2obj[child_obj.id] = child_obj
              fill_childgoid2obj(childgoid2obj, child_obj)
docs: Fill childgoid2obj with all child key GO IDs and their objects.