code: private Logger internalGetLogger(String name) {
      assert name != null : "Name was null";
      Logger rv = instances.get(name);
  
      if (rv == null) {
        Logger newLogger = null;
        try {
          newLogger = getNewInstance(name);
        } catch (Exception e) {
          throw new RuntimeException("Problem getting logger", e);
        }
        Logger tmp = instances.putIfAbsent(name, newLogger);
        // Return either the new logger we've just made, or one that was
        // created while we were waiting
        rv = tmp == null ? newLogger : tmp;
      }
  
      return (rv);
    }
docs: Get an instance of Logger from internal mechanisms.