Two children with the same key #28

There is an occurring issue in the library

When two different tags are on the same level in the HTML tree structure, react logs an error:
Encountered two children with the same key, 0. Keys should be unique so that components maintain their identity across updates. Non-unique keys may cause children to be duplicated and/or omitted — the behavior is unsupported and could change in a future version.

Sample HTML causing the issue: <div><p>a</p><span>b</span></div>