code: function invert(object) {
      var index = -1,
          props = keys(object),
          length = props.length,
          result = {};
  
      while (++index < length) {
        var key = props[index];
        result[object[key]] = key;
      }
      return result;
    }
docs: Creates an object composed of the inverted keys and values of the given object.
  
  @static
  @memberOf _
  @category Objects
  @param {Object} object The object to invert.
  @returns {Object} Returns the created inverted object.
  @example
  
  _.invert({ 'first': 'fred', 'second': 'barney' });
  // => { 'fred': 'first', 'barney': 'second' }