A Color class has a constructor that accepts three integer parameters: red, green and blue components in the range of 0 ... 255 with 0 representing no contribution of the component and 255 being the most intense value for that component. The effect of full or semi-transparency can be achieved by adding another component to the color called an alpha channel. This value can also be defined to be in the range of 0...255 with 0 representing opaque or totally non-transparent, and 255 representing full transparency. Define a class AlphaChannelColor to be a subclass of the Color class. AlphaChannelColor should have the following: - an integer instance variable alpha - a constructor that accepts four parameters: red, green, blue and alpha values in that order. The first three should be passed up to the Color class' constructor, and the alpha value should be used to initialize the alpha instance variable. - a getter (accessor) method for the alpha instance variable