lib/rufus/tokyo/cabinet/abstract.rb
def putdup (k, v)

      lib.tcbdbputdup(
        as_btree, k, Rufus::Tokyo.blen(k), v, Rufus::Tokyo.blen(v))
    end
def putdup (k, v)

      lib.tcbdbputdup(
        as_btree, k, Rufus::Tokyo.blen(k), v, Rufus::Tokyo.blen(v))
    end
--

 BTREE methods

++
 This is a B+ Tree method only, puts a value for a key who has
 [potentially] multiple values.