code: function each (obj, fn) {
        var key;
        for (key in obj) {
          if (Object.hasOwnProperty.call(obj, key)) {
            fn(key);
          }
        }
      }
docs: /*!
  Handy shortcut for doing a for-in loop. This is not a "normal" each
  function, it is optimized for Shifty.  The iterator function only receives
  the property name, not the value.
  @param {Object} obj
  @param {Function(string)} fn