code: private void removeBuffer(W buffer) {
          createdBufs.decrementAndGet();
          if (bufferMonitor.remove(buffer) == null) {
              if (logger.isLoggable(Level.FINE)) {
                  logger.log(Level.WARNING,
                      "Attempt to remove unknown buffer from pool.",
                      new Throwable());
              } else {
                  logger.warning("Attempt to remove unknown buffer from pool.");
              }
          }
      }
docs: Removes the buffer from the pool.
  
  @param buffer the buffer to remove