truffle单元测试的使用
引入@openzeppelin/test-helpers
const { ether, BN, expectRevert, expectEvent, constants, time, balance, send } = require('@openzeppelin/test-helpers');
引入@openzeppelin/test-helpers
const { ether, BN, expectRevert, expectEvent, constants, time, balance, send } = require('@openzeppelin/test-helpers');