//克隆map
	function cloneMap(map) {
		let obj= Object.create(null);
		for (let[k,v] of map) {
			obj[k] = v;
		}
		obj = JSON.stringify(obj);
		obj = JSON.parse(obj);
		let tmpMap = new Map();
		for (let k of Object.keys(obj)) {
			tmpMap.set(k,obj[k]);
		}
	  	return tmpMap;
	}
	//克隆set
	function cloneSet(set) {
		let obj = JSON.stringify([...set.values()]);
		obj = JSON.parse(obj);
		let tmpSet = new Set();
		obj.forEach(function(value,i){
			tmpSet.add(value);
		})
		return tmpSet;
	}