# File lib/fog/compute/models/virtual_box/storage_controller.rb, line 23
        def attach(medium, port, device = 0)
          requires :identity, :machine
          with_session do |session|
            session.machine.attach_device(identity, port, device, medium.device_type, medium.instance_variable_get(:@raw))
            session.machine.save_settings
          end
          true
        end