static int Operation(int index) {
DataCalculation(index);
Console.WriteLine("Operation {0}", index);
return i * 10;
}

static void DemoDo_Sequential() {
Console.WriteLine("=== Sekvenn voln ===");
Operation(1);
Operation(2);
Operation(3);
Operation(4);
}
static void DemoDo_Parallel() {
Console.WriteLine("=== Voln Parallel.Do ===");
Parallel.Do(
() => Operation(1),
() => Operation(2),
() => Operation(3),
() => Operation(4));
}
