   ###
 
   prev: (callback) ->
-    throw new Error 'Illegal state' unless isValid
-    lock()
-    @self.prev afterSeek callback
+    @self.prev @_wrapSeek callback, true
 
 
   ###

      callback = options
      options = null

    throw new Error 'Missing callback' unless callback

    callback null, getKey(options), getValue(options)


  ###

  valid: -> @_valid


  ###
