Filters a command frame received from a client.
Filters a command frame received from a client. returns None if the filter wants to drop the frame.
Filters a command frame being sent client.
Filters a command frame being sent client. returns None if the filter wants to drop the frame.
A Protocol filter can filter frames being sent/received to and from a client. It can modify the frame or even drop it.
(Since version 1.7) Please use the ProtocolFilter3 interface instead