- * SORT_MERGE merge items with identical keys, needs the following functions:
- * void PREFIX_write_merged(struct fastbuf *f, SORT_KEY **keys, uns n, byte *buf)
+ * SORT_UNIFY merge items with identical keys, needs the following functions:
+ * void PREFIX_write_merged(struct fastbuf *f, SORT_KEY **keys, void **data, uns n, void *buf)