`seeNumberOfElements()` doesn't count <input>s with Bootstrap's `.custom-control-input` class

[ThomasLandauer]

Next problem with Bootstrap custom radio button after #21

seeNumberOfElements() doesn't count those radiobuttons:

<input type="radio" class="custom-control-input">

This is probably because of z-index:-1 in Bootstrap's CSS:

.custom-control-input{position:absolute;left:0;z-index:-1;width:1rem;height:1.22rem;opacity:0}

Background: When using Bootstrap's custom radiobuttons, the standard browser widget is replaced by some other widget (SVG?) for nicer graphics.

I'm filing this here mainly to see if somebody else encounters it. A possible solution could be to set a configuration parameter in acceptance.suite.yml to switch the concerned methods' behavior to be compatible with Bootstrap.

In my case I can't look at the page's source code (what I'm guessing that e.g. seeNumberOfElementsInDOM() is doing), since I'm showing/hiding some radiobuttons with JavaScript, and I need to assert their visibility. My workaround: Count the labels instead:

$I->seeNumberOfElements(['css' => 'div#foobar label'], 7);