    # File lib/fog/virtual_box/models/compute/server.rb, line 117
            def save
              unless identity
                requires :name, :os
                self.raw = service.create_machine(nil, name, os)
                service.register_machine(raw)
                with_session do |session|
                  for attribute in [:description, :memory_size, :rtc_use_utc, :vram_size]
                    session.machine.send("#{attribute}=""#{attribute}=", attributes[attribute])
                  end
                  session.machine.save_settings
                end
                true
              else
                raise Fog::Errors::Error.new('Updating an existing server is not yet implemented. Contributions welcome!')
              end
            end