code: public boolean containsKey(Object id) {
          final String methodName = "containsKey()";
          boolean found = false;
  
          if (!this.invalidationBuffer.contains(id)) {
              try {
                  rwLock.readLock().lock();
                  found = object_cache.containsKey(id);
              } catch (Throwable t) {
                  com.ibm.ws.ffdc.FFDCFilter.processException(t, "com.ibm.ws.cache.HTODDynacache.containsKey", "1877", this);
                  if (tc.isDebugEnabled())
                      Tr.debug(tc, methodName, "cacheName=" + this.cacheName + "\nException: " + ExceptionUtility.getStackTrace(t));
              } finally {
                  rwLock.readLock().unlock();
              }
          }
          return found;
      }
docs: ***********************************************************************
  containsKey()
  Check whether the cache id exists in the disk or not.
  ***********************************************************************