Count rows starting with prefix

row_count_with_prefix.clj

(let [f1 (PrefixFilter. (hb/to-bytes "0 "))]
  (hb/with-table [table (hb/table "foo_bar_table")]
    (hb/with-scanner [scanner (hb/scan table
                                       :filter f1
                                       :caching 1000)]
      (loop [n 0]
        (if (seq (.next scanner 1000))
          (recur (+ n (count (.next scanner 1000))))
          n)))))

Find the bug because of which this code is returning about half of the actual number of rows starting with prefix ``0 ''. :-)