TestBuilder.kt

class OrderBuilder {
  var id: Long = Random().nextLong()
  var userId = 1L
  var from = 100.btc
  var to = 10.ltc
  var rate = 0.5
  var status = NEW

  private fun build() = Order(id, userId, from, to, rate, status)

  companion object {
    fun anOrder(block: OrderBuilder.() -> Unit) = OrderBuilder().apply(block).build()
    val anOrder = anOrder {}
  }
}

//Usage
import com.getchange.test.OrderBuilder.Companion.anOrder

val order = anOrder
val sentOrder = anOrder {status = SENT}