namespace System.Threading.Tasks.Dataflow
{
    public static class DataflowBlock
    {
        public static Task<int> Choose<T1, T2, T3>(ISourceBlock<T1> source1, Action<T1> action1, ISourceBlock<T2> source2, Action<T2> action2, ISourceBlock<T3> source3, Action<T3> action3);
    }
}