How to add class to ActiveForm in Yii 2.0 framework?

I'd like to add a class to the form like:

<form role="form" action="/login" method="POST" class="userform">

How should I rewrite this for Yii 2.0 ActiveForm class?

The same question is for this structure inside of the form tag:

<div class="ui-grid-solo">
     <div class="ui-grid-a">
          <label for="name">Full Name</label>
          <input type="text" name="login" id="login" value="" data-clear-btn="true" data-mini="true">
          <label for="password">Password</label>
          <input type="password" name="password" id="password" value="" data-clear-btn="true" autocomplete="off" data-mini="true">
          <input type="checkbox" name="remind" id="remind" value="1">
          <label for="remind">Remember me</label>
          <br>
          <input type="submit" value="Login" onclick="this.form.submit();">
     </div>
</div>

In Yii2 I don't think 'htmlOptions' works. Just 'options' is correct, e.g.

<?php
    $form = ActiveForm::begin(
        [
            'action' => '/login',
            'options' => [
                'class' => 'userform'
             ]
        ]
    );
    // ... add all your inputs here for example:
    echo $form->field($model, 'login');
    ActiveForm::end();
?>