Open any page in Moodle (preferably in Chrome) Open JS console Open source tab, hit Ctrl+O and type mcore Search for the applyZIndex function and add a breakpoint at it's first line Hit escape to bring up the JS console For each of these, you should expect the debugger to break at the applyZIndex: // Grab all of the dialogue types Y.use('moodle-core-notification');   // Test base dialogue d = new M.core.dialogue({visible: true}); // Check... d.destroy(true);   // Test ajaxException dialogue d = new M.core.ajaxException({visible: true}); // Check... d.destroy(true);   // Test exception dialogue d = new M.core.exception({visible: true}); // Check... d.destroy(true);   // Test confirmation dialogue d = new M.core.confirm({visible: true}); // Check... d.destroy(true);   // Test alert dialogue d = new M.core.alert({visible: true}); // Check... d.destroy(true);