code: @Override
      protected String getCacheKey() {
          String key = null;
          if (cacheResultInvocationContext != null) {
              HystrixGeneratedCacheKey hystrixGeneratedCacheKey =
                      defaultCacheKeyGenerator.generateCacheKey(cacheResultInvocationContext);
              key = hystrixGeneratedCacheKey.getCacheKey();
          }
          return key;
      }
docs: {@inheritDoc}.