Fatal error: Uncaught Error: Class 'OxidEsales\TestingLibrary\UnitTestCase' not found in /www/shop/vendor/oxid-esales/oxideshop-ce/tests/Integration/Core/EmailBuilderTest.php:17 Stack trace: #0 {main} thrown in /www/shop/vendor/oxid-esales/oxideshop-ce/tests/Integration/Core/EmailBuilderTest.php on line 17