Encapsulate handling of all Bokeh Protocol messages a Bokeh server may
A Bokeh server may be expected to receive any of the following protocol
The job of ProtocolHandler is to direct incoming messages to the right
specialized handler for each message type. When the server receives a new
message on a connection it will call handler with the message and the
connection that the message arrived on. Most messages are ultimately
handled by the ServerSession class, but some simpler messages types
such as SERVER-INFO-REQ may be handled directly by ProtocolHandler.
Any unexpected messages will result in a ProtocolError.
Delegate a received message to the appropriate handler.
message (Message) – The message that was receive that needs to be handled
connection (ServerConnection) – The connection that received this message