+ /**
+ * Iterate over the results that are "close" to a particular key in
+ * the datacache. "close" is defined as numerically larger than @a
+ * key (when interpreted as a circular address space), with small
+ * distance.
+ *
+ * @param cls closure (internal context for the plugin)
+ * @param key area of the keyspace to look into
+ * @param num_results number of results that should be returned to @a iter
+ * @param iter maybe NULL (to just count)
+ * @param iter_cls closure for @a iter
+ * @return the number of results found
+ */
+ unsigned int (*get_closest) (void *cls,
+ const struct GNUNET_HashCode *key,
+ unsigned int num_results,
+ GNUNET_DATACACHE_Iterator iter,
+ void *iter_cls);
+