code: public Map<String, Map<String, Object>> getBooleanMapping() {
          if (null == this.booleanMapping) {
              this.booleanMapping = new HashMap<String, Map<String, Object>>(16);
          }
          return booleanMapping;
      }
docs: 获取属性到boolean值的映射
  
  @return 返回属性到boolean值的映射