Setting an environment for a codeception Acceptance Test -

i've been trying out codeception acceptance tests. i'd able set environment use selenium tests don't need javascript can use faster phpbrowser driver , tests need js can this:

$scenario->env('selenium');  $i = new webguy($scenario);  $i->wantto('ensure teacher login works');  etc... 

however when set env test runs , says acceptance tests (0) - no tests run. commenting out line , tests run.

class_name: webguy modules:     enabled:         - phpbrowser         - webhelper         - webdebug     config:         selenium2:           url: 'http://test.r5'           browser: firefox         phpbrowser:             url: 'http://test.r5' env:     selenium:          modules:             enabled:                 - selenium2             config:                 url: 'http://test.r5'                 browser: firefox 

how can set 1 acceptance test run selenium?

ref http://codeception.com/docs/07-advancedusage#environments