    # File lib/chef/provider/group.rb, line 107
          def action_modify
            if @group_exists
              if compare_group
                manage_group
                @new_resource.updated_by_last_action(true)
                Chef::Log.info("#{@new_resource} modified")
              end
            else
              raise Chef::Exceptions::Group, "Cannot modify #{@new_resource} - group does not exist!"
            end
          end