docs: private String getMapResultString(Map result) {
          StringBuilder sb = new StringBuilder();
          Iterator<Entry> i = result.entrySet().iterator();
          if (!i.hasNext()) {
              return "{}";
          }
          sb.append('{');
          for (;;) {
              Entry e = i.next();
              Object key = e.getKey();
              Object value = e.getValue();
              // 注意: 修改为getResultString(e)进行递归处理
              sb.append(key == this ? "(this Map)" : getResultString(key));
              sb.append('=');
              // 注意: 修改为getResultString(e)进行递归处理
              sb.append(value == this ? "(this Map)" : getResultString(value));
              if (!i.hasNext()) {
                  return sb.append('}').toString();
              }
              sb.append(", ");
          }
      }