apollo-core/src/main/java/com/ctrip/framework/apollo/core/utils/DeferredLogger.java/DeferredLogger/debug
class DeferredLogger:  @Override
  public void debug(String s, Object... objects) {
    if (isEnabled()) {
      DeferredLogCache.debug(logger, s, objects);
    } else {
      logger.debug(s, objects);
    }
  }