docs: protected static void validateZooKeeperConfig(Properties props) {
  		if (props.getProperty("zookeeper.connect") == null) {
  			throw new IllegalArgumentException("Required property 'zookeeper.connect' has not been set in the properties");
  		}
  		if (props.getProperty(ConsumerConfig.GROUP_ID_CONFIG) == null) {
  			throw new IllegalArgumentException("Required property '" + ConsumerConfig.GROUP_ID_CONFIG
  					+ "' has not been set in the properties");
  		}
  
  		try {
  			//noinspection ResultOfMethodCallIgnored
  			Integer.parseInt(props.getProperty("zookeeper.session.timeout.ms", "0"));
  		}
  		catch (NumberFormatException e) {
  			throw new IllegalArgumentException("Property 'zookeeper.session.timeout.ms' is not a valid integer");
  		}
  
  		try {
  			//noinspection ResultOfMethodCallIgnored
  			Integer.parseInt(props.getProperty("zookeeper.connection.timeout.ms", "0"));
  		}
  		catch (NumberFormatException e) {
  			throw new IllegalArgumentException("Property 'zookeeper.connection.timeout.ms' is not a valid integer");
  		}
  	}