Perform any necessary changes to the form values prior to storage. There is no need for this function to actually store the data.
Overrides FilterPluginBase::value_submit
function value_submit($form, &$form_state) {
// Drupal's FAPI system automatically puts '0' in for any checkbox that
// was not set, and the key to the checkbox if it is set.
// Unfortunately, this means that if the key to that checkbox is 0,
// we are unable to tell if that checkbox was set or not.
// Luckily, the '#value' on the checkboxes form actually contains
// *only* a list of checkboxes that were set, and we can use that
// instead.
$form_state['values']['options']['value'] = $form['value']['#value'];
}