ws.scala

case class WSRequest(url: String, headers: Map[String, String] = Map.empty) {
  def withHeaders(_headers: (String, String)*): WSRequest = {
    copy(headers = Map.from(_headers))
  }
}

val r0 = WSRequest("asdf", Map("foo" -> "bar"))
val r1 = WSRequest("asdf")
val r2 = r1.withHeaders("foo" -> "bar") // syntactic sugar for r1.copy(headers = ...)

(r0 == r2) == true
(r1 == r2) == false