/**
     * init graph
     */
    public MetadataGraph(int nVertices) {
        init(nVertices, 2 * nVertices);
    }

    public MetadataGraph(int nVertices, int nEdges) {
        init(nVertices, nEdges);
    }
    // ------------------------------------------------------------------------
    /**
     * construct a single vertex
     */
    public MetadataGraph(MetadataGraphVertex entry) throws MetadataResolutionException {

    @Override
    public ClasspathContainer transform(MetadataGraph dirtyGraph, ArtifactScopeEnum scope, boolean resolve)
            throws MetadataGraphTransformationException {
        try {
            if (dirtyGraph == null || dirtyGraph.isEmpty()) {
                return null;
            }

            MetadataGraph cleanGraph = conflictResolver.resolveConflicts(dirtyGraph, scope);

        try {
            // edge case - single vertex graph
            if (vertices.size() == 1) {
                return new MetadataGraph(entry);
            }

            final ArtifactScopeEnum requestedScope = ArtifactScopeEnum.checkScope(scope);

            MetadataGraph res = new MetadataGraph(vertices.size());
            res.setVersionedVertices(false);
            res.setScopedVertices(false);