public async Task SendAsync(TRequest argument)
 {
     await Task.WhenAll(InvocationInfos.Select(async info =>
     {
         await info.InvokeAsync(argument);
     }));
 }
 public async Task <IEnumerable <TResult> > SendAsync(TRequest argument)
 {
     return(await Task.WhenAll(InvocationInfos.Select(async info =>
     {
         var result = await info.InvokeAsync(argument);
         return (TResult)result;
     })));
 }