Laravel Fake Mailable Fails After Few Emails Inside Application Are Sent.

MailFake.php

<?php

class Test
{
    /**
     * Api Helper
     *
     * @var \Helper\Api
     */
    protected $api;

    /**
     * Module repository
     *
     * @var $repository
     */
    protected $repository;

    /**
     * Load required helpers for cest
     *
     * @param \Helper\Api $api
     */
    protected function _inject(\Helper\Api $api)
    {
        $this->api = $api;
    }

    /**
     * Return module repository
     *
     * @return UserRepository
     */
    public function _getRepository() : UserRepository
    {
        return $this->api->getApplication()->make('Modules\Users\Services\User\UserService')->getUserRepository();
    }

    /**
     * Actions executed before cest
     *
     * @param ApiTester $I
     */
    public function _before(ApiTester $I)
    {
    }

    /**
     * Actions executed after cest
     *
     * @param ApiTester $I
     */
    public function _after(ApiTester $I)
    {
    }

    /**
     * Test user activation
     *
     * @param ApiTester $I
     *
     * @return void
     */
    public function test(ApiTester $I) : void
    {
        // Prevent actual email being sent
        Mail::fake();

        // Do some stuff
        // Email 1 inside application is sent..

        Mail::assertSent(Action1Mail::class, function (Action1Maill $mail) {
            return $mail->getVal() == 1;
        });

        // Do some stuff
        // Email 2 inside application is sent..

        // Boom, error:  [BadMethodCallException] Method assertSent does not exist.
        // Because: get_class(app('mailer')) == Illuminate\Mail\Mailer
        // And no more: get_class(app('mailer')) == Illuminate\Support\Testing\Fakes\MailFake
        Mail::assertSent(Action2Mail::class, function (Action2Mail $mail) {
            return $mail->getVal() == 2;
        });

    }
}