code: protected synchronized void invalidateCacheWrappers() {
          if (com.ibm.ejs.ras.TraceComponent.isAnyTracingEnabled() && logger.isLoggable(Level.FINE)) // 306998.15
              logger.entering(CLASS_NAME, "invalidateCacheWrappers"); // 569469
  
          if (cacheWrappers != null) {
              // invalidate all the cache wrappers that wrap this target.
              Iterator i = cacheWrappers.iterator();
  
              while (i.hasNext()) {
                  ServletReferenceListener w = (ServletReferenceListener) i.next();
                  if (com.ibm.ejs.ras.TraceComponent.isAnyTracingEnabled() && logger.isLoggable(Level.FINE)) // 306998.15
                      logger.logp(Level.FINE, CLASS_NAME, "invalidateCacheWrappers", "servlet reference listener -->[" + w + "]");
                  w.invalidate();
              }
  
              cacheWrappers = null;
          }
          if (com.ibm.ejs.ras.TraceComponent.isAnyTracingEnabled() && logger.isLoggable(Level.FINE)) // 306998.15
              logger.exiting(CLASS_NAME, "invalidateCacheWrappers"); // 569469
      }
docs: which makes a call to invalidateCacheWrappers