presto-spi/src/main/java/io/prestosql/spi/block/RunLengthEncodedBlock.java/RunLengthEncodedBlock/toString
class RunLengthEncodedBlock:    @Override
    public String toString()
    {
        StringBuilder sb = new StringBuilder(getClass().getSimpleName());
        sb.append("positionCount=").append(positionCount);
        sb.append(", value=").append(value);
        sb.append('}');
        return sb.toString();
    }