title: Yii2 & Codeception - Enabling tester module in unit testing
body: <p>I use Yii2 and build-in codeception and want to write unit tests. In the documentation of codeception I´ve found this example test:</p>
  
  <pre><code>function testUserCanBeActivatedWithValidKey()
  {
      // lookup for user with Eloquent API
      $user = User::find($this-&gt;user_id);
      // executing action
      $isActivated = $user-&gt;activate('123456'));
      // performing assertion
      $this-&gt;assertTrue($isActivated);
      // checking that data was actually saved into database
      $this-&gt;tester-&gt;seeRecord('users', [
          'id' =&gt; $this-&gt;user_id,
          'is_active' =&gt; 1
       ]);
  }
  </code></pre>
  
  <p>But when I´m trying to write the test myself, there is no <code>$this-&gt;tester</code> Object. How can I benefit from methods like <code>seeInDatabase()</code>? </p>