);                                 auto path_trace_it = deepest_child_edge.find(find(path.back()));                                 while (path_trace_it != deepest_child_edge.end()) {                                     // Follow the deepest child relationships until they run out.                                     path.push_back(path_trace_it->second);                                     path_trace_it = deepest_child_edge.find(find(path.back()));                                 }                             }                                                          // 