undefined artisan method when testing console commands

I have a simple console command that prints ‘Hello, World!’ into the terminal. It’s like this:

<?php

namespace AppConsoleCommands;

use IlluminateConsoleCommand;

class SimpleCommand extends Command
{
    /**
     * The name and signature of the console command.
     *
     * @var string
     */
    protected $signature = 'app:simple-command';

    /**
     * The console command description.
     *
     * @var string
     */
    protected $description = 'Command description';

    /**
     * Execute the console command.
     */
    public function handle()
    {
        $this->line('Hello, World!');
    }
}

and I want to write a unit test for this command

<?php

namespace TestsUnitConsoleCommands;

use PHPUnitFrameworkTestCase;

class SimpleCommandTest extends TestCase
{
    /**
     * Test a console command.
     */
    public function test_console_example(): void
    {
        $this->artisan();
    }
}

But after I ran the test, I got an error says:

Call to undefined method TestsUnitConsoleCommandsSimpleCommandTest::artisan()

I’ve copied codes mostly from the documentation and suprised that they’re not working. Is there anything I’m missing? Or do I need to install some package? Or am I in the wrong namespace or something?