run() method for lazy-execution

Allows you to write tests avoiding checks if ($scenario->running()) { /* code */ }

Future test will look like:

    /* code */
    $I->run(function() {
         // do somthing deferred
    });
    /* code */

Real example from docs if you use run() method:

    <?php
    function save(\CodeGuy $I, \Codeception\Scenario $scenario)
        $I->execute('Comment::save', array('post_id' => 5);
        $I->run(function() {
            DB::updateCounters();
        });
        $I->seeInDatabase('posts',array('id' => 5, 'comments_count' => 1));
    ?>

http://en.wikipedia.org/wiki/Cyclomatic_complexity