The following important information from PEP 3156 does not appear in the asyncio library documentation:

"""Datagram protocols have connection_made() and connection_lost() methods with the same signatures as stream protocols."""

Indeed, reading the docs it looks like only ``Protocol`` and ``SubprocessProtocol`` have these methods. (See https://docs.python.org/3.4/library/asyncio-protocol.html#connection-callbacks)

The quick fix is to change the lines 275-276 in ``Doc/library/asyncio-protocol.rst`` from:

    These callbacks may be called on Protocol and SubprocessProtocol instances:

to

    These callbacks may be called on Protocol, DatagramProtocol, and SubprocessProtocol instances: