presto-orc/src/main/java/io/prestosql/orc/reader/SliceDirectColumnReader.java/SliceDirectColumnReader/readAllNullsBlock
class SliceDirectColumnReader:    private RunLengthEncodedBlock readAllNullsBlock()
    {
        return new RunLengthEncodedBlock(new VariableWidthBlock(1, EMPTY_SLICE, new int[2], Optional.of(new boolean[] {true})), nextBatchSize);
    }