code: @Override
  	public void unsubscribe(String subscriptionName) throws JMSException
      {
      	externalAccessLock.readLock().lock();
      	try
  		{
  	        checkNotClosed();
  	        if (StringTools.isEmpty(subscriptionName))
  	            throw new FFMQException("Empty subscription name","INVALID_SUBSCRIPTION_NAME");
  	
  	        // Remove remaining subscriptions on all topics
  	        engine.unsubscribe(connection.getClientID(), subscriptionName);
  		}
      	finally
      	{
      		externalAccessLock.readLock().unlock();
      	}
      }
docs: /* (non-Javadoc)
  @see javax.jms.Session#unsubscribe(java.lang.String)