code: public void removeWriter(LockEntry writer)
      {
          checkTimedOutLocks();
  
          String oidString = writer.getOidString();
          ObjectLocks objectLocks = null;
          synchronized (locktable)
          {
          	objectLocks = (ObjectLocks) locktable.get(oidString);
          }
          if (objectLocks == null)
          {
              return;
          }
          else
          {
  			/**
          	 * MBAIRD, last one out, close the door and turn off the lights.
          	 * if no locks (readers or writers) exist for this object, let's remove
          	 * it from the locktable.
          	 */
          	synchronized (locktable)
          	{
          		Map readers = objectLocks.getReaders();
          		objectLocks.setWriter(null);
          		// no need to check if writer is null, we just set it.
              	if (readers.size() == 0)
              	{
              		locktable.remove(oidString);
              	}
          	}
          }
      }
docs: remove a writer lock entry for transaction tx on object obj
  from the persistent storage.