static <D, S> ChannelServiceProtocolBuilder<D, S> builder() {
        return new ChannelServiceProtocolBuilder<>();
    }
@author youngjin.kim2

This protocol should contain the information which must be shared between server and client
for communication through channel.
<br>
At the channel service, there always be a demand from client, and supplies from server. The demand are
carried through channel, and listened by server. The supplies are sent through channel, and received by client.
<br>
By the number of supplies, the channel service can be classified into two types: Mono and Flux.
Mono is a channel service which sends only one supply, and Flux is a channel service which sends multiple supplies.

@see ChannelServiceServerProtocol
@see ChannelServiceClientProtocol
channel/src/main/java/com/navercorp/pinpoint/channel/service/ChannelServiceProtocol.java