docs: private static boolean repStep(
  			BufferedReader in,
  			boolean readConsoleInput) throws IOException, InterruptedException {
  
  		// wait until CLIENT_POLLING_INTERVAL is over or the user entered something.
  		long startTime = System.currentTimeMillis();
  		while ((System.currentTimeMillis() - startTime) < CLIENT_POLLING_INTERVAL_MS
  			&& (!readConsoleInput || !in.ready())) {
  			Thread.sleep(200L);
  		}
  		//------------- handle interactive command by user. ----------------------
  
  		if (readConsoleInput && in.ready()) {
  			String command = in.readLine();
  			switch (command) {
  				case "quit":
  				case "stop":
  					return false;
  
  				case "help":
  					System.err.println(YARN_SESSION_HELP);
  					break;
  				default:
  					System.err.println("Unknown command '" + command + "'. Showing help:");
  					System.err.println(YARN_SESSION_HELP);
  					break;
  			}
  		}
  
  		return true;
  	}