ArkTS中，HashMap对象怎么转成 json字符串？

const map1: HashMap<string, string> = new HashMap(); 
map1.set("a", "avalue"); 
map1.set("b", "bValue"); 
 
const jsonObject:Record<string,Object> = {}; 
map1.forEach((value,key) => { 
  if (key != undefined && value != undefined) { 
    jsonObject[key] = value; 
  } 
}) 
const jsonString = JSON.stringify(jsonObject) 
console.log('jsonString', jsonString)