Demonstrate a runtime error (NoSuchMethodError)

Fut.scala

trait Fut[ A ] { def set( i: A ) : Unit }
object Fut {
   def empty[ A ]() : Fut[ A ] = new Fut[ A ] {
      final case class Set( value : A )
      def receive( x : AnyRef ) { x match {
         case Set( value ) => println( "Got " + value )
      }}
      def set( value : A ) { receive( Set( value ))}
   }
}

val g = Fut.empty[ Int ]()
g.set( 33 )