./vendor/bin/codecept run acceptance JunkCept.php -d

JunkCept.php

<?php

$I = new \AcceptanceTester\SpringboardSteps($scenario);

$I->amOnPage('/');

$I->executeInSelenium(function (\Webdriver $webdriver) {
    $executor = $webdriver->getCommandExecutor();
    $session = $executor->execute('getSession', array());
    if ($session['browserName'] == 'phantomjs') {
        // do something special
        codecept_debug(var_export($session, TRUE));

        codecept_debug('using phantomjs');
    }
    else {
        // do some other thing.
        codecept_debug('not using phantomjs');
    }

});