@Override
    void cancel() {
        cancellationTokenSource.cancel()
    }

    @Override
    CancellationToken token() {
        return cancellationTokenSource.token()
    }

    public <T> T withCancellation(@DelegatesTo(ProjectConnection) @ClosureParams(value = SimpleType, options = ["org.gradle.tooling.CancellationToken"]) Closure<T> cl) {
        try {
            cancellationTokenSource = GradleConnector.newCancellationTokenSource()

        events.testClassesAndMethods.size() == (supportsEfficientClassFiltering() ? 3 : 4)
    }

    public <T> T withCancellation(@ClosureParams(value = SimpleType, options = ["org.gradle.tooling.CancellationToken"]) Closure<T> cl) {
        return cancellationTokenSource.withCancellation(cl)
    }

    def "listener errors are rethrown on client side"() {
        given:
        collectDescriptorsFromBuild()

    }

    public <T> T runBuild(List<String> tasks = ["build"], Closure<T> underBuild) {
        if (projectConnection) {
            buildResult = new TestResultHandler()

            cancellationTokenSource.withCancellation { CancellationToken token ->
                // this is here to ensure that the lastModified() timestamps actually change in between builds.