abstract class Minify implements TransformAction<Parameters> { // <1>
    interface Parameters extends TransformParameters {         // <2>
        @Input
        Map<String, Set<String>> getKeepClassesByArtifact()
        void setKeepClassesByArtifact(Map<String, Set<String>> keepClasses)
// end::artifact-transform-minify[]
        @Input
        Long getTimestamp()
        void setTimestamp(Long timestamp)
// tag::artifact-transform-minify[]
    }