json parsing

package models;

import play.api.libs.json._
import play.api.libs.functional.syntax._
import play.api.libs.json.Json

case class ScribbleModel(
    _comment: String,
    url: String,
    frames: Seq[LineModel]
)


case class LineModel(
   width: Int,
   color: String,
   points: Seq[Tuple2[Float,Float]]
)

object ScribbleModel{
    implicit val scribbleModelReads = Json.reads[ScribbleModel];
}

object LineModel{
   implicit def lineModelReads = Json.reads[LineModel];
   //                            ^^^^^^^^^^^^^^^^^^^^^
   // No implicit reads for Seq[(Float,Float)]
}