package com.gu

package object pandomainauth {
  case class PublicKey(key: String) extends AnyVal
  case class PrivateKey(key: String) extends AnyVal
  case class Secret(secret: String) extends AnyVal
}

package com.gu

package object pandomainauth {
  case class PublicKey(key: String)
  case class PrivateKey(key: String)
  case class Secret(secret: String)
}

--- 
+++ 
@@ -1,7 +1,7 @@
 package com.gu
 
 package object pandomainauth {
-  case class PublicKey(key: String)
-  case class PrivateKey(key: String)
-  case class Secret(secret: String)
+  case class PublicKey(key: String) extends AnyVal
+  case class PrivateKey(key: String) extends AnyVal
+  case class Secret(secret: String) extends AnyVal
 }
Use AnyVal to automatically unwrap at compile time
