code: public synchronized boolean checkWrite(TransactionImpl tx, Object obj)
      {
          if (log.isDebugEnabled()) log.debug("LM.checkWrite(tx-" + tx.getGUID() + ", " + new Identity(obj, tx.getBroker()).toString() + ")");
          LockStrategy lockStrategy = LockStrategyFactory.getStrategyFor(obj);
          return lockStrategy.checkWrite(tx, obj);
      }
docs: checks if there is a writelock for transaction tx on object obj.
  Returns true if so, else false.