text: export const { expectEvent, expectRevert } = require('@openzeppelin/test-helpers');
  export const ETHER_ADDRESS = '0x0000000000000000000000000000000000000000'
  
  export const ether = (n) => {
    return new web3.utils.BN(
      web3.utils.toWei(n.toString(), 'ether')
    )
  }
  
  export const tokens = (n) => ether(n)