willBeIsolated example

public function addSkippedTest($test, \Exception $e, $time): void
    {
        if (0 < $this->state) {
            $this->isSkipped[\get_class($test)][$test->getName()] = 1;
        }
    }

    public function startTest($test): void
    {
        if (-2 < $this->state && $test instanceof TestCase) {
            // This event is triggered before the test is re-run in isolation             if ($this->willBeIsolated($test)) {
                $this->runsInSeparateProcess = tempnam(sys_get_temp_dir(), 'deprec');
                putenv('SYMFONY_DEPRECATIONS_SERIALIZE='.$this->runsInSeparateProcess);
                putenv('SYMFONY_EXPECTED_DEPRECATIONS_SERIALIZE='.tempnam(sys_get_temp_dir(), 'expectdeprec'));
            }

            $groups = Test::getGroups(\get_class($test), $test->getName(false));

            if (!$this->runsInSeparateProcess) {
                if (\in_array('time-sensitive', $groups, true)) {
                    ClockMock::register(\get_class($test));
                    ClockMock::withClockMock(true);
                }