presto-spi/src/main/java/io/prestosql/spi/predicate/Marker.java/Marker/getPrintableValue
class Marker:    public Object getPrintableValue(ConnectorSession session)
    {
        if (!valueBlock.isPresent()) {
            throw new IllegalStateException("No value to get");
        }
        return type.getObjectValue(session, valueBlock.get(), 0);
    }