Fatal error: Uncaught Error: Class "PHPUnit_Framework_TestCase" not found in /var/www/Library-Exercises/01-Library/vendor/spipu/html2pdf/Tests/Parsing/HtmlLexerTest.php:21 Stack trace: #0 {main} thrown in /var/www/Library-Exercises/01-Library/vendor/spipu/html2pdf/Tests/Parsing/HtmlLexerTest.php on line 21