public void First_should_throw_when_aggregate_is_null(
[Values(false, true)] bool async)
{
IAggregateFluent <Person> subject = null;
Action action;
if (async)
{
action = () => subject.FirstAsync().GetAwaiter().GetResult();
}
else
{
action = () => subject.First();
}
action.ShouldThrow <ArgumentNullException>().And.ParamName.Should().Be("aggregate");
}