public async Task OnExecuteAsyncRegistersDelegate()
        {
            var invoked = false;

            _instanceUnderTest.OnExecuteAsync(_ =>
            {
                invoked = true;
                return(Task.CompletedTask);
            });
            await _instanceUnderTest.RuntimeCommand.InvokeAsync(_testOptions, CancellationToken.None);

            invoked.ShouldBeTrue();
        }