message: Used key property
diff: @@ -74,7 +74,7 @@ class Motion<T> extends React.Component<MotionProps<T>, any> {
  return newItem;
  })
  )
  - .sort((a, b) => a.index !== b.index ? a.index - b.index : getKey(a).length - getKey(b).length);
  + .sort((a, b) => a.index !== b.index ? a.index - b.index : a.key.length - b.key.length);
  return {items, moving: items.filter(({rest}) => !rest).length !== 0};
  }
  static areEqual(from = {}, to = {}) {
  