Fatal error: Uncaught Error: Class "JsonMapperTest_DerivedClass" not found in C:\xampp\htdocs\public\vendor\apimatic\jsonmapper\tests\JsonMapperTest\DerivedClass2.php:7 Stack trace: #0 {main} thrown in C:\xampp\htdocs\public\vendor\apimatic\jsonmapper\tests\JsonMapperTest\DerivedClass2.php on line 7