code: @Override
  	public void close() throws IOException {
  		try {
  			if (session != null) {
  				session.close();
  			}
  		} catch (Exception e) {
  			LOG.error("Error while closing session.", e);
  		}
  
  		try {
  			if (cluster != null) {
  				cluster.close();
  			}
  		} catch (Exception e) {
  			LOG.error("Error while closing cluster.", e);
  		}
  	}
docs: Closes all resources used.