FML/Script/Features/RadioButtonGroupFeature.php
public function addRadioButton(CheckBox $radioButton)
    {
        if (!in_array($radioButton, $this->radioButtons, true)) {
            array_push($this->radioButtons, $radioButton);
        }
        return $this;
    }
public function addRadioButton(CheckBox $radioButton)
    {
        if (!in_array($radioButton, $this->radioButtons, true)) {
            array_push($this->radioButtons, $radioButton);
        }
        return $this;
    }
public function addRadioButton ( CheckBox $ radioButton ) { if ( ! in_array ( $ radioButton , $ this -> radioButtons , true ) ) { array_push ( $ this -> radioButtons , $ radioButton ) ; } return $ this ; }
Add a new RadioButton

@api
@param CheckBox $radioButton RadioButton
@return static
Add a new RadioButton