[Test]
public void Meters_Are_Checked_In_Desired_Time()
{
    var meterLoader = new Mock<IAmActiveMetersLoader>();
    meterLoader.Setup(x => x.ReloadAllActiveMeters()).Returns(() => new List<long> {1, 2, 3});
    var sut = PrepareSystemUnderTest(meterLoader);
    sut.DoPeriodicCheckIfNeeded();

    meterLoader.Verify(x => x.ReloadAllActiveMeters(), Times.Exactly(1));
}