// will delete each orphaned "from" vertex, but will never delete the "to" vertex
func (g *Graph) deleteEdges_locked(fromType, toType vertexType, toNamespace, toName string) {
	// get the "to" side
	toVert, exists := g.getVertex_rlocked(toType, toNamespace, toName)
	if !exists {
		return
	}

	// delete all edges between vertices of fromType and toVert
	neighborsToRemove := []*namedVertex{}

        this.instantiator = instantiator;
        this.ruleActionAdapter = ruleActionAdapter;
        this.moduleIdentifierNotationParser = NotationParserBuilder
            .toType(ModuleIdentifier.class)
            .fromCharSequence(new ModuleIdentifierNotationConverter(moduleIdentifierFactory))
            .toComposite();
        this.ruleExecutor = ruleExecutor;