@get:Input
    @get:Optional
    abstract val buildTimestamp: Property<Date>

    @get:OutputDirectory
    abstract val receiptFolder: DirectoryProperty

    fun buildTimestampFrom(provider: Provider<String>) {
        buildTimestamp = provider.map { buildTimestampString -> timestampFormat.parse(buildTimestampString) }
    }

    @TaskAction
    fun generate() {