public async Task WhenIUpdateBabySitter(
string firstName,
string lastName,
int standard,
int betweenBedtimeAndMidnight,
int afterMidnight)
{
var sitters = await _fixture.GetBabySitters();
var sitter = sitters.Where(s => s.FirstName == firstName)
.Single(s => s.LastName == lastName);
await _fixture.UpdateBabySitter(
sitter.Id,
firstName,
lastName,
standard,
betweenBedtimeAndMidnight,
afterMidnight);
}