apollo-portal/src/main/java/com/ctrip/framework/apollo/portal/component/RetryableRestTemplate.java/RetryableRestTemplate/parseAdminServiceAccessTokens
class RetryableRestTemplate:  private Map<Env, String> parseAdminServiceAccessTokens(String accessTokens) {
    Map<Env, String> tokenMap = Maps.newHashMap();
    try {
      // try to parse
      Map<String, String> map = GSON.fromJson(accessTokens, ACCESS_TOKENS);
      map.forEach((env, token) -> {
        if (Env.exists(env)) {
          tokenMap.put(Env.valueOf(env), token);
        }
      });
    } catch (Exception e) {
      logger.error("Wrong format of admin service access tokens: {}", accessTokens, e);
    }
    return tokenMap;
  }