code: function(object, memo, callback) {
         each(object, function(key, value){
           memo = (callback.length == 2 ?
                     callback(memo, value):
                       callback(memo, key, value)) ||
                         memo
         })
         return memo
       }
docs: Iterate with memo.
  
  @param  {hash, array} object
  @param  {object} memo
  @param  {function} callback
  @return {object}
  @api public