Alias: Mutable vs Immutable 015 Define a class ImmutablePen with: one private instance variable: color of pen (string) a constructor that has one parameter that represents this ImmutablePen's color (String) getColor(): a getter for the instance variable Define a class MutablePen with: one private instance variable: color (String) a constructor that takes one parameter that represents this MutablePen's color (String) getColor(): a getter for the instance variable setColor(): a setter for the instance variable override method clone () so that it returns a new MutablePen whose color is the same color as this MutablePen