# File lib/fog/image/openstack/v2/models/image.rb, line 77
          def update(attr = nil)
            requires :id
            client_attributes = attr || @attributes
            server_attributes = service.images.get(id).attributes

            json_patch = build_update_json_patch(client_attributes, server_attributes)

            merge_attributes(
              service.update_image(id, json_patch).body
            )
            self
          end