code: protected <S> S getProperty(IClientConfigKey<S> key, @Nullable IClientConfig requestConfig, S defaultValue) {
          if (requestConfig != null && requestConfig.get(key) != null) {
              return requestConfig.get(key);
          } else {
              return clientConfig.get(key, defaultValue);
          }
      }
docs: Resolve the final property value from,
  1. Request specific configuration
  2. Default configuration
  3. Default value
  
  @param key
  @param requestConfig
  @param defaultValue
  @return