return source;
    }

    public void setSource(MetadataGraphVertex source) {
        this.source = source;
    }

    public MetadataGraphVertex getTarget() {
        return target;
    }

    public void setTarget(MetadataGraphVertex target) {
        this.target = target;
    }

    @Override
    public String toString() {
        return "[ " + "FROM:("

        checkVertex(vFrom);
        checkVertex(vTo);

        checkVertices();

        checkEdge(e);
        checkEdges();

        e.setSource(vFrom);
        e.setTarget(vTo);

        vFrom.setCompareVersion(versionedVertices);
        vFrom.setCompareScope(scopedVertices);

        List<MetadataGraphEdge> exList = excidentEdges.computeIfAbsent(vFrom, k -> new ArrayList<>());

            //                                    if( e2.getPomOrder() == e1.getPomOrder() )
            //                                        return
            // e1.getTarget().toString().compareTo(e2.getTarget().toString() );
            //
            //                                    return e2.getPomOrder() - e1.getPomOrder();
            //                                }
            //

                                    : edge.getSource().getMd().toString(),
                            edge.isResolved(),
                            edge.getTarget() == null
                                    ? null
                                    : edge.getTarget().getMd().getError());
                    MetadataGraphVertex newV = res.addVertex(newMd);