code: public synchronized void checkValidPoolProperty(JobInProgress job)
        throws InvalidJobConfException {
      if (!strictPoolsMode) {
        return;
      }
  
      JobConf conf = job.getJobConf();
      // Pool name needs to be lower cased.
      String poolName = conf.get(EXPLICIT_POOL_PROPERTY);
      if (poolName == null) {
        return;
      } else {
        poolName = poolName.toLowerCase();
      }
  
      if (poolNamesInAllocFile.contains(poolName)) {
        return;
      }
  
      throw new InvalidJobConfException(
          "checkValidPoolProperty: Pool name " +
          conf.get(EXPLICIT_POOL_PROPERTY) + " set with Hadoop property " +
          EXPLICIT_POOL_PROPERTY + " does not exist.  " +
          "Please check for typos in the pool name.");
    }
docs: A quick check for to ensure that if the pool name is set and we are in a
  strict pools mode, then the pool must exist to run this job.
  
  @param job Job to check
  @throws InvalidJobConfException