def dependencyGenerator = new DependencyGenerator()
        def numberOfProjects = 0
        dependencyGenerator.numberOfProjects = numberOfProjects

        when:
        def layerSizes = dependencyGenerator.calculateLayerSizes()

        then:
        layerSizes.isEmpty()

        when:
        def projectsInLayer = dependencyGenerator.splitProjectsInLayers(layerSizes)

        then:
        projectsInLayer.isEmpty()

 * This way the function returns the same results each time it is evaluated.
 */
class DependencyGenerator {
    Integer numberOfProjects
    Integer maxProjectDependencies = 5

    def calculateLayerSizes() {
        Deque<Integer> layerSizes = new ArrayDeque<>()
        recursiveLayers(numberOfProjects, layerSizes)
        layerSizes as List
    }