public function delete(UnitTester $I)
{
$I->wantTo('Delete from cache by using APC(u) as cache backend');
$key = '_PHCA' . 'data-delete';
$cache = new Apc(new Data(['lifetime' => 20]));
$I->assertFalse($cache->delete('non-existent-keys'));
$I->haveInApc($key, 1);
$I->assertTrue($cache->delete('data-delete'));
$I->dontSeeInApc($key);
}