It seems like `asyncio.timeout` is going to be added in 3.4.5, 3.5.2 and 3.6. The current live documentation of python 3.4 and python 3.5.1 does not include a comment regarding it is not yet available in the current released versions of python. The documentation should include a `.. versionadded:: 3.4.5`, `.. versionadded:: 3.5.2` or `.. versionadded:: 3.6` according to the branch.