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)