### Description

The `sendRequest` method is asynchronous and notifies a 
`TransportResponseHandler` when it completes the excecution
(successfully or unsuccessfully). 

When opening the connection we only catch `NodeNotConnectedException`
( https://github.com/elastic/elasticsearch/blob/main/server/src/main/java/org/elasticsearch/transport/TransportService.java#L719 ) which is currently fine as no implementations
throw other type of exception however, it'd be best to catch `Exception` here
so the `handler` gets notified of potential exceptions (as opposed to the caller
having to `try/catch` the call to `sendRequest`)
server/src/main/java/org/elasticsearch/cluster/coordination/PublicationTransportHandler.java
}
                    compatibleClusterStateDiffReceivedCount.incrementAndGet();
                    logger.debug(
                        "received diff cluster state version [{}] with uuid [{}], diff size [{}]",
                        incomingState.version(),
                        incomingState.stateUUID(),
                        request.bytes().length()
                    );
                    final PublishWithJoinResponse response = acceptState(incomingState);
                    lastSeenClusterState.compareAndSet(lastSeen, incomingState);
                    return response;
                }
            }
        } finally {
            IOUtils.close(in);
        }
    }
    private PublishWithJoinResponse acceptState(ClusterState incomingState) {
        assert incomingState.nodes().isLocalNodeElectedMaster() == false
            : "should handle local publications locally, but got " + incomingState;
        return handlePublishRequest.apply(new PublishRequest(incomingState));
    }
    public PublicationContext newPublicationContext(ClusterStatePublicationEvent clusterStatePublicationEvent) {
        final PublicationContext publicationContext = new PublicationContext(clusterStatePublicationEvent);
        boolean success = false;
        try {
            
            
            
            publicationContext.buildDiffAndSerializeStates();