cakephpのcheckboxでseparatorは効かない

-- before -- -- between -- あああ いいい ううう えええ -- after --

<?php echo $this->BootstrapForm->input('status', array(
    'div' => false,
    'label' => false,
    'options' => $statuses,
    'multiple' => 'checkbox',
    'before' => '-- before --',
    'between' => '-- between --',
    'after' => '-- after --',
    'separator' => '-- separator --',
)); ?>