code: public void setExperts(Map<String, Class<? extends JdbcExpert>> experts) {
          this.experts = experts;
          this._experts = new LinkedHashMap<Pattern, Class<? extends JdbcExpert>>();
          for (Entry<String, Class<? extends JdbcExpert>> entry : experts.entrySet()) {
              //忽略大小写,并且让换行符与.能够匹配
              _experts.put(Pattern.compile(entry.getKey(), Pattern.DOTALL & Pattern.CASE_INSENSITIVE), entry.getValue());
          }
      }
docs: 在 fromJson 的时候，会被调用