code: function prefixKeys(object, prefix, delimiter) {
      var prefixed = {};
  
      forEach(object, function (value, key) {
        key = [prefix, key].join(delimiter || '');
        prefixed[key] = value;
      });
  
      return prefixed;
    }
docs: /* Prefixes all keys in an object with a prefix and delimiter.
  
  object    - An Object with keys to prefix.
  prefix    - A String to add as a prefix.
  delimiter - A delimiter to seperate the prefix and key (default: "").
  
  Examples
  
  var obj = {a: 1, b: 2, c: 3}
  prefixKeys(obj, 'prefix', '.');
  // => {'prefix.a': 1, 'prefix.b': 2 ...}
  
  Returns new Object with prefixed keys.