/**
     * Returns all tasks, in the order started.
     */
    List<Operation> getTasks() {
        assertHasZeroOrMoreTrees()
        def taskOperations = operations.findAll { it.task } as List
        taskOperations.forEach { it.assertIsTask() }
        return taskOperations
    }

    /**
     * Returns all successful operations, in the order started.
     */
    List<Operation> getSuccessful() {

    }

    def assertEmptyInputsTask(ProgressEvents.Operation taskOperation) {
        if (targetVersion < GradleVersion.version("3.4")) {
            assert taskOperation.result.upToDate
        } else {
            assert taskOperation.result instanceof TaskSkippedResult
            assert taskOperation.result.skipMessage == "NO-SOURCE"
        }
        true
    }

    def goodCode() {