When a consumer application is receiving messages from a channel or stream, it gets a None when the client is unexpectedly disconnected from the broker.
This None notification does not arrive if the broker cleanly disconnects from the client by sending a DISCONNECT packet.
When a consumer application is receiving messages from a channel or stream, it gets a
Nonewhen the client is unexpectedly disconnected from the broker.This
Nonenotification does not arrive if the broker cleanly disconnects from the client by sending aDISCONNECTpacket.