KotlinBuilder.kt

data class ClipAPI(var id: String?,
                   var type: String?,
                   var url: String?,
                   var mgid: String?,
                   var title: String?,
                   var format: String?,
                   var description: String?,
                   var duration: DurationAPI?,
                   var images: List<ImageAPI>?,
                   var season: SeasonAPI?,
                   var episode: EpisodeAPI?,
                   var originalPublishDate: PublishDate?) {

    private constructor(builder: Builder) : this(builder.id,
            builder.type,
            builder.url,
            builder.mgid,
            builder.title,
            builder.format,
            builder.description,
            builder.duration,
            builder.images,
            builder.season,
            builder.episode,
            builder.originalPublishDate)

    class Builder(val id: String) {
        var type: String? = null
        var url: String? = null
        var mgid: String? = null
        var title: String? = null
        var format: String? = null
        var description: String? = null
        var duration: DurationAPI? = null
        var images: List<ImageAPI>? = null
        var season: SeasonAPI? = null
        var episode: EpisodeAPI? = null
        var originalPublishDate: PublishDate? = null

        fun build() = ClipAPI(this)
    }
}

class UsageExample {

    fun example() {
        ClipAPI.Builder(id = "ABC")  //required
                .apply {
                    url = "http://blar.com"  //optionals
                    description = "example"
                }.build()
    }

}