问Remix的文档测试test#2失败

EN

pragma solidity ^0.5.3;
contract sender {
    address private owner;
    constructor() public {
    owner = msg.sender;
    }
    function updateOwner(address newOwner) public {
        require(msg.sender == owner, "only current owner can update owner");
        owner = newOwner;
    }
    function getOwner() public view returns (address) {
        return owner;
    }
}

pragma solidity 0.5.3;

// This import is automatically injected by Remix
import "remix_tests.sol"; 
import "tests/sender.sol";
import "remix_accounts.sol";


    
    // File name has to end with '_test.sol', this file can contain more than one testSuite contracts
    contract testSuite is sender{
        //sender obj;
        address acc0;
        address acc1;
        address acc2;
        function beforeAll() public {
            acc0 = TestsAccounts.getAccount(0); 
            acc1 = TestsAccounts.getAccount(1);
            acc2 = TestsAccounts.getAccount(2);
        }
        function testInitialOwner() public {
           Assert.equal(getOwner(), acc0, 'owner should be acc0');
        }
        function updateOwnerOnce() public {
            // check method caller is as expected
            Assert.ok(msg.sender == acc0, 'caller should be default account i.e. acc0');
            // update owner address to acc1
           updateOwner(acc1);
            // check if owner is set to expected account
           Assert.equal(getOwner(), acc1, 'owner should be updated to acc1');
        }
        function updateOwnerOnceAgain() public {
            // check if caller is custom and is as expected
            Assert.ok(msg.sender == acc1, 'caller should be custom account i.e. acc1');//This is failing
        }
    }

testSuite (tests/sender_test.sol)
✓ Test initial owner
✓ Update owner once
✘ Update owner once again
Error Message:
"caller should be custom account i.e. acc1"
Assertion:
Expected value should be
'true'
Received value:
false
Skipping the remaining tests of the function.
Result for tests/sender_test.sol
Passing: 2
Failing: 1
Total time: 0.30s