* @return The filter used to determine which of the artifacts in the dependency graph should be traversed or
     *         {@code null} to collect all transitive dependencies.
     */
    public ArtifactFilter getCollectionFilter() {
        return collectionFilter;
    }

    public ArtifactResolutionRequest setCollectionFilter(ArtifactFilter filter) {
        this.collectionFilter = filter;

        return this;
    }