code: @Override
    public void removeChange(DiffEntry change) {
      Path path = new Path(change.getOldPath());
      if (path.depth() == NODE_FILE_DEPTH) {
        removeDataNode(change);
      } else if (path.depth() == EDGE_FILE_DEPTH) {
        removeFlowEdge(change);
      }
    }
docs: Remove an element (i.e. either a {@link DataNode} or a {@link FlowEdge} from the {@link FlowGraph} for
  a renamed or deleted {@link DataNode} or {@link FlowEdge} file.
  @param change