/**
  * Decrements the retain count for a given browser object.
  *
  * @param browser to be released
  */
 public synchronized void releaseBrowser(ERXBrowser browser) {
   String key = _computeKey(browser);
   ERXMutableInteger count = _decrementReferenceCounterForKey(key);
   if (count == null) {
     // Perhaps forgot to call registerBrowser() but try to remove the browser for sure
     _browserPool().removeObjectForKey(key);
   } else if (count.intValue() <= 0) {
     _browserPool().removeObjectForKey(key);
     _referenceCounters().removeObjectForKey(key);
   }
 }