extract_selected_and_disabled

# File actionview/lib/action_view/helpers/form_options_helper.rb, line 806
        def extract_selected_and_disabled(selected)
          if selected.is_a?(Proc)
            [selected, nil]
          else
            selected = Array.wrap(selected)
            options = selected.extract_options!.symbolize_keys
            selected_items = options.fetch(:selected, selected)
            [selected_items, options[:disabled]]
          end
        end