private static JSONObject buildDefaultQuotaEnforcerSourceInfoPairJson() {
    JSONObject jsonObject = new JSONObject();
    jsonObject.put(ENFORCER_STR, "com.github.ambry.quota.capacityunit.AmbryCUQuotaEnforcerFactory");
    jsonObject.put(SOURCE_STR, "com.github.ambry.quota.capacityunit.AmbryCUQuotaSourceFactory");
    JSONArray jsonArray = new JSONArray();
    jsonArray.put(jsonObject);
    return new JSONObject().put(QUOTA_ENFORCER_SOURCE_PAIR_INFO_STR, jsonArray);
  }
Build the default quota enforcer and source pair json.
@return JSONObject representing the pair json.
ambry-api/src/main/java/com/github/ambry/config/QuotaConfig.java