static ChannelProvider pair(PubChannelProvider pub, SubChannelProvider sub) {
        return new PairedChannelProvider(pub, sub);
    }
@author youngjin.kim2

ChannelProvider provides PubChannel, and SubChannel by the key.
<br>
In distributed system, A pair of PubChannel, and SubChannel are connected each other if they have the same key.
In the other word, even if the two processes are located at the different side of the network, they can communicate
with each other if they have the same key.
channel/src/main/java/com/navercorp/pinpoint/channel/ChannelProvider.java