code: function composeEasingObject (fromTweenParams, easing) {
        var composedEasing = {};
  
        if (typeof easing === 'string') {
          each(fromTweenParams, function (prop) {
            composedEasing[prop] = easing;
          });
        } else {
          each(fromTweenParams, function (prop) {
            if (!composedEasing[prop]) {
              composedEasing[prop] = easing[prop] || DEFAULT_EASING;
            }
          });
        }
  
        return composedEasing;
      }
docs: /*!
  Creates a usable easing Object from either a string or another easing
  Object.  If `easing` is an Object, then this function clones it and fills
  in the missing properties with "linear".
  @param {Object} fromTweenParams
  @param {Object|string} easing