Play json merge files for case class with more than 22 fields

Question

I am trying to split a format into several tuples so that it can handle more than 22 fields in the case class. However, I got the error "and is not a member of play.api.libs.json.Format" . How to combine several formats for the case class?

val fields1to2: Format[(Int, String)] = ( (__ \ "a").format[Int] and (__ \ "b").format[String] ).tupled val fields3to4: Format[(Boolean, List[Int])] = ( (__ \ "c").format[Boolean] and (__ \ "d").format[List[Int]] ).tupled implicit val hugeCaseClassReads: Format[Huge] = ( fields1to2 and fields3to4 // "value and is not a member of play.api.libs.json.Format" ) { case ((a, b), (c, d)) => Huge(a, b, c, d) }