Warning: Unsupported declare 'strict_types' in C:\xampp\htdocs\esales2\vendor\theseer\tokenizer\tests\XMLSerializerTest.php on line 1

Fatal error: Class 'PHPUnit\Framework\TestCase' not found in C:\xampp\htdocs\esales2\vendor\theseer\tokenizer\tests\XMLSerializerTest.php on line 9