presto-orc/src/main/java/io/prestosql/orc/reader/BooleanColumnReader.java/BooleanColumnReader/readNonNullBlock
class BooleanColumnReader:    private Block readNonNullBlock()
            throws IOException
    {
        verifyNotNull(dataStream);
        byte[] values = dataStream.getSetBits(nextBatchSize);
        return new ByteArrayBlock(nextBatchSize, Optional.empty(), values);
    }