code: @Override
      public void renew(IEntityLock lock, int duration) throws LockingException {
          if (isValid(lock)) {
              Date newExpiration = getNewExpiration(duration);
              getLockStore().update(lock, newExpiration);
              ((EntityLockImpl) lock).setExpirationTime(newExpiration);
          } else {
              throw new LockingException("Could not renew " + lock + " : lock is invalid.");
          }
      }
docs: Extends the expiration time of the lock by some service-defined increment.
  
  @param lock IEntityLock
  @exception LockingException