PlayFramework with Scala and Morphia

I keep getting this exception:

Oops: CannotCompileException An unexpected error occured caused by exception CannotCompileException: [source error] ds() not found in models.dc

What is wrong with my code?

Here is models.ds

package models

import com.google.code.morphia.annotations._

@Embedded
class ds{

  @Indexed
  var xs : Double=0

  @Indexed
  var xc : Double=0

  @Indexed
  var ys : Doubl开发者_开发问答e=0

  @Indexed
  var yc : Double=0

  @Indexed
  var zs : Double=0

  @Indexed
  var zc : Double=0
}

Here is models.dc

package models

import com.google.code.morphia.annotations.{Embedded, Entity, Indexed}

@Entity
class dc{

  @Indexed
  var name : String = null

  @Embedded
  var summary : ds = new ds()
}

Never Mind. Because I was using the Play Framework Morphia Module, I forgot to extend Model.

This is what caused the error.

Can anyone explain why this happened?