### 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`)
test/framework/src/main/java/org/elasticsearch/transport/AbstractSimpleTransportTestCase.java
@Override
                    public void handleResponse(final TransportResponse.Empty response) {
                        fail("handle response should not be invoked");
                    }
                    @Override
                    public void handleException(final TransportException exp) {
                        te.set(exp);
                    }
                }
            );
            assertThat(te.get(), not(nullValue()));
            return te.get();
        }
    }
    private void closeConnectionChannel(Transport.Connection connection) {
        StubbableTransport.WrappedConnection wrappedConnection = (StubbableTransport.WrappedConnection) connection;
        TcpTransport.NodeChannels channels = (TcpTransport.NodeChannels) wrappedConnection.getConnection();
        CloseableChannel.closeChannels(channels.getChannels().subList(0, randomIntBetween(1, channels.getChannels().size())), true);
    }
    @SuppressForbidden(reason = "need local ephemeral port")
    protected InetSocketAddress getLocalEphemeral() throws UnknownHostException {
        return new InetSocketAddress(InetAddress.getLocalHost(), 0);
    }
    protected Set<TcpChannel> getAcceptedChannels(TcpTransport transport) {
        return transport.getAcceptedChannels();
    }
    /**
     * Connect to the specified node with the default connection profile
     *
     * @param service service to connect from