docs: public void addPreMessageReceivedEventListener(Executor executor, PreMessageReceivedEventListener listener) {
          peersPreMessageReceivedEventListeners.add(new ListenerRegistration<>(checkNotNull(listener), executor));
          for (Peer peer : getConnectedPeers())
              peer.addPreMessageReceivedEventListener(executor, listener);
          for (Peer peer : getPendingPeers())
              peer.addPreMessageReceivedEventListener(executor, listener);
      }