public void replaceStatement(Statement oldstat, Statement newstat) {
    cancellationManager.checkCanceled();
    for (StatEdge edge : oldstat.getAllPredecessorEdges()) {
      oldstat.removePredecessor(edge);
      edge.getSource().changeEdgeNode(EdgeDirection.FORWARD, edge, newstat);
      newstat.addPredecessor(edge);
    }

    for (StatEdge edge : oldstat.getAllSuccessorEdges()) {
      oldstat.removeSuccessor(edge);
      edge.setSource(newstat);
      newstat.addSuccessor(edge);
    }

    int statindex = stats.getIndexByKey(oldstat.id);
    stats.removeWithKey(oldstat.id);
    stats.addWithKeyAndIndex(statindex, newstat, newstat.id);

    newstat.setParent(this);
    newstat.post = oldstat.post;

    if (first == oldstat) {
      first = newstat;
    }

    List<StatEdge> lst = new ArrayList<>(oldstat.getLabelEdges());

    for (int i = lst.size() - 1; i >= 0; i--) {
      StatEdge edge = lst.get(i);
      if (edge.getSource() != newstat) {
        newstat.addLabeledEdge(edge);
      }
      else {
        if (this == edge.getDestination() || this.containsStatementStrict(edge.getDestination())) {
          edge.closure = null;
        }
        else {
          this.addLabeledEdge(edge);
        }
      }
    }

    oldstat.getLabelEdges().clear();
  }
public void replaceStatement(Statement oldstat, Statement newstat)