ScalaTypeBounds.scala

  trait Thing
  trait Vehicle extends Thing
  class Car extends Vehicle
  class Jeep extends Car
  class Coupe extends Car
  class Motorcycle extends Vehicle
  class Vegetable

  class Parking[A](val place: A)

  val parkingVehicle:Parking[Vehicle] = new Parking(new Jeep)
  val parkingCar:Parking[Car] = new Parking(new Jeep)
  val parkingJeep:Parking[Jeep] = new Parking(new Jeep)
  val parkingMotorCycle:Parking[Vehicle] = new Parking(new Motorcycle)
  val parkingVegtable = new Parking(new Vegetable)

  // we can create type parameter restrictions
  // To create them, we make use of Scala type bounds.

  class ParkingTypeBound[A <: Vehicle](val place:A)

  val parkJeep:ParkingTypeBound[Vehicle] = new ParkingTypeBound(new Jeep)


  class ParkingLowerJeep[A >: Jeep ](val place:A)
  class Wrangler extends Jeep

  val parkWrangler = new ParkingLowerJeep(new Wrangler)

  // Vegatable can be Parked as its anyref anf super type of jeep
  val parkVeg = new ParkingLowerJeep(new Vegetable)

  class ParkingUpperLower[A >:Jeep <:Vehicle](val place:A)
  val parkWrangVehicle = new ParkingUpperLower(new Wrangler)
//  val parkVegUPLOw = new ParkingUpperLower(new Vegetable)   //Wotn Work as its not subtype of Vehicle