I've created a form field, which is just Yes/No

class EditableYesNoField extends EditableMultipleOptionField {
	
	static $singular_name = 'Yes/No Field';
	
	static $plural_name = 'Yes/No Fields';
	

	function getFormField() {
		$optionSet = $this->Options();
		$options = array('yes' => 'Yes', 'no' => 'No');
		
		/*if($optionSet) {
			foreach( $optionSet as $option ) {
				$options[$option->Title] = $option->Title;
			}	
		}*/
		
		return new OptionsetField($this->Name, $this->Title, $options);
	}
}

This works fine but how do I create a group of them?