presto-orc/src/main/java/io/prestosql/orc/stream/BooleanOutputStream.java/BooleanOutputStream/getCheckpoints
class BooleanOutputStream:    @Override
    public List<BooleanStreamCheckpoint> getCheckpoints()
    {
        checkState(closed);
        ImmutableList.Builder<BooleanStreamCheckpoint> booleanStreamCheckpoint = ImmutableList.builder();
        List<ByteStreamCheckpoint> byteStreamCheckpoints = byteOutputStream.getCheckpoints();
        for (int groupId = 0; groupId < checkpointBitOffsets.size(); groupId++) {
            int checkpointBitOffset = checkpointBitOffsets.get(groupId);
            ByteStreamCheckpoint byteStreamCheckpoint = byteStreamCheckpoints.get(groupId);
            booleanStreamCheckpoint.add(new BooleanStreamCheckpoint(checkpointBitOffset, byteStreamCheckpoint));
        }
        return booleanStreamCheckpoint.build();
    }