Why : void is not used in test cases?

[datamweb]

@kenjis I usually read the tests written by you. You usually wrote the test in Figure :
public function testYourTest(): void { // test code }
I know this is optional, but it's weird why you didn't do it!
May I ask why you did not use void here?

shield/tests/Authentication/Authenticators/AccessTokenAuthenticatorTest.php

Line 51 in 3a7894c

public function testLogout()

[kenjis]

The commit is just to move the test files.
I did not change anything. PhpStorm just did refactoring.

Writing return type is a good practice.