public void GivenTimePeriodInput_ThenCorrectDateRangeIsReturned(DateTime currentDateTime, TimePeriod inputTimePeriod, DateRange expectedDateRange)
{
var expectedDateTimeUtcNow = new DateTimeOffset(currentDateTime);
_mockSystemClock.Setup(clock => clock.UtcNow).Returns(expectedDateTimeUtcNow);
var helper = new TimePeriodHelper(_mockSystemClock.Object);
var returnedDateRange = helper.ResolveDateRange(inputTimePeriod);
Assert.Equal(expectedDateRange, returnedDateRange);
}