* If ``MPD_HOST`` is not set, then look for a socket in ``${XDG_RUNTIME_DIR}/mpd/socket``
* If there is no socket use ``localhost``
* If ``MPD_PORT`` is not set, then use ``6600``
* If ``MPD_TIMEOUT`` is not set, then uses :py:obj:`musicpd.CONNECTION_TIMEOUT`
* If ``MPD_HOST`` is not set, then look for a socket in ``${XDG_RUNTIME_DIR}/mpd/socket``
* If there is no socket use ``localhost``
* If ``MPD_PORT`` is not set, then use ``6600``
* If ``MPD_TIMEOUT`` is not set, then uses :py:obj:`musicpd.CONNECTION_TIMEOUT`