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());
}
