If included, the message that should be sent if the client disconnects.
-`topic`*(string)*:
-`message`*(string)*:
-`qos` *(int): 0, 1 or 2
-`retain`: *(bool)* new clients subscribing to `topic` will receive this message
### `broker` *(mapping)*
-`uri`*(string)*: Broker connection URL, *must conform to MQTT or URI scheme: `[mqtt(s)|ws(s)]://<username:password>@HOST:port`*
TLS certificates used to verify the broker's authenticity.
-`cafile`*(string)*: Path to a file of concatenated CA certificates in PEM format. See [Certificates](https://docs.python.org/3/library/ssl.html#ssl-certificates) for more info.
-`capath`*(string)*: Path to a directory containing several CA certificates in PEM format, following an [OpenSSL specific layout](https://docs.openssl.org/master/man3/SSL_CTX_load_verify_locations/).
-`cadata`*(string)*: Either an ASCII string of one or more PEM-encoded certificates or a bytes-like object of DER-encoded certificates.