gpointer data);
const BlueSkyRangesetItem *bluesky_rangeset_lookup(BlueSkyRangeset *rangeset,
uint64_t offset);
+const BlueSkyRangesetItem *bluesky_rangeset_lookup_next(BlueSkyRangeset *rangeset, uint64_t offset);
/* Storage interface. This presents a key-value store abstraction, and can
* have multiple implementations: in-memory, on-disk, in-cloud. */