apollo-biz/src/main/java/com/ctrip/framework/apollo/biz/service/ItemService.java/ItemService/getItemValueLengthLimit
class ItemService:  private int getItemValueLengthLimit(long namespaceId) {
    Map<Long, Integer> namespaceValueLengthOverride = bizConfig.namespaceValueLengthLimitOverride();
    if (namespaceValueLengthOverride != null && namespaceValueLengthOverride.containsKey(namespaceId)) {
      return namespaceValueLengthOverride.get(namespaceId);
    }
    return bizConfig.itemValueLengthLimit();
  }