code: @Override
      public boolean exists(String key) {
          final String KEY = calcCacheKey(key);
          try (Jedis jedis = getJedis()) {
              if (keyMode == KeyMode.HASH) {
                  return jedis.hget(SafeEncoder.encode(getName()), SafeEncoder.encode(KEY)) != null;
              } else {
                  return jedis.get(SafeEncoder.encode(KEY)) != null;
              }
          } catch (Exception e) {
              throw e instanceof CacheException ? (CacheException) e : new CacheException(e);
          }
      }
docs: {@inheritDoc}