//C# Pipeline example
var tasks = myObject
    .Select(o => o.MyString)
    .Where(s => s != null)
    .Select(s => new Request() { Message = s })
    .Select(r => r.Send(mediator))
    .ToArray();

await Task.WhenAll(tasks); //There should be an extension `Task WhenAll(this IEnumerable<Task>)`

//C# Non-Pipeline example
await Task.WhenAll(
    Enumerable.ToArray(
        Enumerable.Select(
            Enumerable.Select(
                Enumerable.Where(
                    Enumerable.Select(
                        myObject,
                        o => o.MyString
                    ),
                    s=> s != null
                ),
                s => new Request() { Message = s }
            ),
            r => mediator.Send(r)
        ),
    )
);


//PowerShell Pipeline example
Get-Process notepad `
    | Stop-Process

//PowerShell Non-Pipeline example
Stop-Process -InputObject ( `
    Get-Process notepad `
)