public void Test_S2CellUnion_InvalidCellIdNotValidWithDebugFlag() { // Manually save and restore flag, to preserve test state in opensource // without gflags. Assert.False(S2CellId.None.IsValid()); var cell_union = S2CellUnion.FromVerbatimNoCheck(new List <S2CellId> { S2CellId.None }); Assert.False(cell_union.IsValid()); }