code: public PersistenceBrokerInternal createPersistenceBroker(PBKey pbKey) throws PBFactoryException
      {
          if (log.isDebugEnabled()) log.debug("Obtain broker from pool, used PBKey is " + pbKey);
  
          /*
          try to find a valid PBKey, if given key does not full match
          */
          pbKey = BrokerHelper.crossCheckPBKey(pbKey);
  
          try
          {
              return createNewBrokerInstance(pbKey);
  
          }
          catch (Exception e)
          {
              throw new PBFactoryException("Borrow broker from pool failed, using PBKey " + pbKey, e);
          }
      }
docs: Always return a new created {@link PersistenceBroker} instance
  
  @param pbKey
  @return
  @throws PBFactoryException