}
final ArtifactResolver resolver = this.getArtifactResolver();
if (resolver == null) {
throw new IllegalStateException("this.getArtifactResolver()", new NullPointerException("this.getArtifactResolver()"));
}
final Collection<? extends Artifact> artifacts = new Artifacts().getArtifactsInTopologicalOrder(project,
dependencyGraphBuilder,
this.getArtifactFilter(),
resolver,
this.getLocalRepository());
Collection<? extends URL> urls = null;