anchor.diff:  val m1 = Movie("The Professional",1994)
   val m2 = Movie("The Fifth Element",1997)
   val m3 = Movie("Memento",1994)
  -val m4 = Movie("Prometheus",2000)
  +val m4 = Movie("Prometheus",2012)
   
   val a1 = Actor(n1,56,Set(m1,m2))
   val a2 = Actor(n2,47,Set(m3,m4))
  
positive.code:     ),
      Movie(
        name = "Prometheus",
        year = 2000
      )
    )
  )
  
negative.code: m1: Movie = Movie(The Professional,1994)
  m2: Movie = Movie(The Fifth Element,1997)
  m3: Movie = Movie(Memento,1994)
  m4: Movie = Movie(Prometheus,2012)
  a1: Actor = Actor(Name(Gary,Some(Freakn),Oldman),56,Set(Movie(The Professional,1994), Movie(The Fifth Element,1997)))
  a2: Actor = Actor(Name(Guy,None,Pearce),47,Set(Movie(Memento,1994), Movie(Prometheus,2012)))
  a3: Actor = Actor(Name(Lance,None,Gatlin),37,Set())
  
  scala> a1.printApply
  