code: public EVCacheClientPool getEVCacheClientPool(String _app) {
          final String app = getAppName(_app);
          final EVCacheClientPool evcacheClientPool = poolMap.get(app);
          if (evcacheClientPool != null) return evcacheClientPool;
          initEVCache(app);
          return poolMap.get(app);
      }
docs: Given the appName get the EVCacheClientPool. If the app is already
  created then will return the existing instance. If not one will be
  created and returned.
  
  @param _app
  - name of the evcache app
  @return the Pool for the give app.
  @throws IOException