def collection_check_boxes2(method, collection, value_method, text_method, options = {}, html_options = {})
      html_options ||= {}
      html_options[:multiple] = 'multiple'
      collection_select2 method, collection, value_method, text_method, options, html_options
    end
def collection_check_boxes2(method, collection, value_method, text_method, options = {}, html_options = {})
      html_options ||= {}
      html_options[:multiple] = 'multiple'
      collection_select2 method, collection, value_method, text_method, options, html_options
    end
Since select2 support multiple choices (checkboxes)