# File lib/simple_form/inputs/grouped_collection_select_input.rb, line 5
      def input(wrapper_options = nil)
        label_method, value_method = detect_collection_methods

        merged_input_options = merge_wrapper_options(input_html_options, wrapper_options)

        @builder.grouped_collection_select(attribute_name, grouped_collection,
                      group_method, group_label_method, value_method, label_method,
                      input_options, merged_input_options)
      end