code: @Override
      public void delete(String key) {
          switch (keyMode) {
          case MONOPOLISTIC:
          case NAMESPACE:
              final String KEY = keyMode == KeyMode.MONOPOLISTIC ? key : calcCacheKeyNamespace(key);
              try {
                  getMemcachedClient().deleteWithNoReply(KEY);
              } catch (Exception e) {
                  throw e instanceof CacheException ? (CacheException) e : new CacheException(e);
              }
              break;
          case XNAMESPACE:
              try {
                  getMemcachedClient().withNamespace(getName(), new MemcachedClientCallable<Void>() {
                      @Override
                      public Void call(MemcachedClient client)
                              throws InterruptedException, MemcachedException {
                          client.deleteWithNoReply(key);
                          return null;
                      }
  
                  });
              } catch (Exception e) {
                  throw e instanceof CacheException ? (CacheException) e : new CacheException(e);
              }
              break;
          default:
              throw new IllegalStateException("Invalid key mode: " + keyMode);
          }
      }
docs: {@inheritDoc}