public void Test_S2CellId_DistanceFromBegin() { Assert.Equal(6, S2CellId.End(0).DistanceFromBegin()); Assert.Equal(6 * (1L << (2 * S2.kMaxCellLevel)), S2CellId.End(S2.kMaxCellLevel).DistanceFromBegin()); Assert.Equal(0, S2CellId.Begin(0).DistanceFromBegin()); Assert.Equal(0, S2CellId.Begin(S2.kMaxCellLevel).DistanceFromBegin()); S2CellId id = S2CellId.FromFacePosLevel(3, 0x12345678, S2.kMaxCellLevel - 4); Assert.Equal(id, S2CellId.Begin(id.Level()).Advance(id.DistanceFromBegin())); }