psalm-plugin-phpunit/Plugin.php

<?php
namespace Psalm\PhpUnitPlugin;

use SimpleXMLElement;
use Psalm\Plugin\PluginEntryPointInterface;
use Psalm\Plugin\RegistrationInterface;

class Plugin implements PluginEntryPointInterface
{
    /** @return void */
    public function __invoke(RegistrationInterface $psalm, SimpleXMLElement $config = null)
    {
        $psalm->addStubFile(__DIR__ . '/stubs/TestCase.php');
    }
}