Part 1

1. in IDE:
   • open /system/debug.php file for editing
   • uncomment 'DBG_CACHE_URLS' => 0, line and save changes
2. on Front-End
   • open hompeage (the / url)
   • confirm, that the homepage is actually displayed (not any other page)
   • confirm, that debugger doesn't contain any notices about $Array usage
   • click on Directory link top menu
   • confirm, that the Directory category is actually displayed (not any other page)
   • confirm, that debugger doesn't contain any notices about $Array usage

Part 2

1. in IDE:
   • copy /index.php into /test.php
   • replace

$application->Run();
$application->Done();

with

$application->UnitConfigReader->iterateConfigs(
    function ($prefix, &$config_data, array $params) {
        echo $prefix . '<br/>' . PHP_EOL;
    },
    array()
);

2. open /test.php in browser or CLI
3. confirm, that prefixes from all registered unit configs are displayed