presto-main/src/main/java/io/prestosql/execution/buffer/PageCodecMarker.java/MarkerSet/equals
class MarkerSet:        @Override
        public boolean equals(Object o)
        {
            if (this == o) {
                return true;
            }
            if (o instanceof MarkerSet) {
                return markers == ((MarkerSet) o).markers;
            }
            return false;
        }