The pubsub package provides facilities for the Publish/Subscribe pattern of message propagation, also known as overlay multicast. The implementation provides topic-based pubsub, with pluggable routing algorithms. The main interface to the library is the PubSub object. You can construct this object with the following constructors: - NewFloodSub creates an instance that uses the floodsub routing algorithm. - NewGossipSub creates an instance that uses the gossipsub routing algorithm. - NewRandomSub creates an instance that uses the randomsub routing algorithm. In addition, there is a generic constructor that creates a pubsub instance with a custom PubSubRouter interface. This procedure is currently reserved for internal use within the package. Once you have constructed a PubSub instance, you need to establish some connections to your peers; the implementation relies on ambient peer discovery, leaving bootstrap and active peer discovery up to the client. To publish a message to some topic, use Publish; you don't need to be subscribed to the topic in order to publish. To subscribe to a topic, use Subscribe; this will give you a subscription interface from which new messages can be pumped.