### 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/transport/TransportService.java
handleSendToLocalException(channel, e, action);
                        }
                        @Override
                        public String toString() {
                            return "processing of [" + requestId + "][" + action + "]: " + request;
                        }
                        @Override
                        public void onAfter() {
                            request.decRef();
                        }
                    }));
                    success = true;
                } finally {
                    if (success == false) {
                        request.decRef();
                    }
                }
            }
        } catch (Exception e) {
            assert false : e;
            handleSendToLocalException(channel, e, action);
        }
    }
    private static void handleSendToLocalException(DirectResponseChannel channel, Exception e, String action) {
        try {
            channel.sendResponse(e);
        } catch (Exception inner) {
            inner.addSuppressed(e);
            logger.warn(() -> "failed to notify channel of error message for action [" + action + "]", inner);
        }