Udash Option JSON codec

Udash_JSON_GenCodec[Option[T]].scala

  /**
    * Udash Option JSON codec for (de)serializing it this way:
    * Some(x) will be serialized as x.
    * None will be serialized as null.
    */
  implicit def optionCodec[T: GenCodec]: GenCodec[Option[T]] =
    create[Option[T]](
      i => i.inputType match {
        case InputType.Null =>
          i.readNull()
          None
        case _ =>
          Some(read[T](i))
      },
      locally {
        case (o, Some(t)) => write[T](o, t)
        case (o, None) => o.writeNull()
      }
    )