    # 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