Fatal error: Uncaught Error: Class 'WP_UnitTestCase' not found in /usr/home/krichard/public_html/theimpression/wp-content/plugins/perfmatters/vendor/deliciousbrains/wp-background-processing/tests/Test_Setup.php:11 Stack trace: #0 {main} thrown in /usr/home/krichard/public_html/theimpression/wp-content/plugins/perfmatters/vendor/deliciousbrains/wp-background-processing/tests/Test_Setup.php on line 11