text: const MainContract = artifacts.require('method2/MainContract.sol');
  const V1 = artifacts.require('method2/V1.sol');
  const V2 = artifacts.require('method2/V2.sol');
  
  contract('Method2', ([admin, _]) => {
    it('should upgrade', async () => {
      let data;
      const mainContract = await MainContract.new();
  
      //Test V1
      const v1 = await V1.new();
      await mainContract.upgrade(v1.address);
      data = await mainContract.getData();
      assert(data.toNumber() === 10);
  
      //Test V2
      const v2 = await V2.new();
      await mainContract.upgrade(v2.address);
      data = await mainContract.getData();
      assert(data.toNumber() === 100);
    });
  });
  