form.php
protected function setWidget($tag)
    {
        if (strtolower($tag->getAttribute('type')) === 'radio') {
            $this->addRadioButton($tag);
        } elseif (strtolower($tag->getAttribute('type')) === 'checkbox') {
            $this->addCheckbox($tag);
        } else {
            $this->widgets[] = $tag;
        }
    }
protected function setWidget($tag)
    {
        if (strtolower($tag->getAttribute('type')) === 'radio') {
            $this->addRadioButton($tag);
        } elseif (strtolower($tag->getAttribute('type')) === 'checkbox') {
            $this->addCheckbox($tag);
        } else {
            $this->widgets[] = $tag;
        }
    }
Sets the widget into the form, grouping radio buttons if any.

@param SimpleWidget $tag   Incoming form control.