@Override
        public Pong ping(Ping ping,Connection connection) {
            if (connection.getResponse() != null)
                return new Pong();
            else
                return new Pong(ErrorMessage.createBackendCommunicationError("No ping response from '" + connection + "'"));
        }
This is the kind of searcher which will be implemented by those who wish to create a searcher which is a
client to a clustered service.
The goal is to make writing this correctly as simple as possible.
container-search/src/test/java/com/yahoo/search/cluster/test/ClusteredConnectionTestCase.java