code: public final long decr(String key, final long delta)
        throws TimeoutException, InterruptedException, MemcachedException {
      key = this.preProcessKey(key);
      return this.sendIncrOrDecrCommand(key, delta, 0, CommandType.DECR, false, this.opTimeout, 0);
    }
docs: /*
  (non-Javadoc)
  
  @see net.rubyeye.xmemcached.MemcachedClient#decr(java.lang.String, int)