code: public static void reload(String key) {
  
          if (!MyStaticValue.ENV.containsKey(key)) { //如果变量中不存在直接删掉这个key不解释了
              remove(key);
          }
  
          putIfAbsent(key, MyStaticValue.ENV.get(key));
  
          KV<String, SmartForest<List<String>>> kv = SYNONYMS.get(key);
  
          init(key, kv, true);
      }
docs: 刷新一个,将值设置为null
  
  @param key
  @return