register method
Registers transport on this bus and notifies all existing nodes of the
new peer (and vice-versa).
Implementation
void register(InMemoryTransport transport) {
final id = transport.nodeId!;
for (final other in _nodes.values) {
other.injectPeerConnected(id);
transport.injectPeerConnected(other.nodeId!);
}
_nodes[id] = transport;
}