# File lib/fog/virtual_box/models/compute/medium.rb, line 47
        def save
          requires :device_type, :location, :read_only

          if File.exists?(location)

            access_mode = if read_only
              :access_mode_read_only
            else
              :access_mode_read_write
            end

            self.raw = service.open_medium(location, device_type, access_mode)

          else

            raise Fog::Errors::Error.new('Creating a new medium is not yet implemented. Contributions welcome!')

          end
        end