create a initalizer for rgbColor

Here´s the task:

In the editor, I’ve declared a struct named RGBColor that models a color object in the RGB space.

Your task is to write a custom initializer method for the object. Using the initializer assign values to the first four properties. Using the values assigned to those properties create a value for the description property that is a string representation of the color object.

For example, given the values 86.0 for red, 191.0 for green, 131.0 for blue and 1.0 for alpha, each of the stored properties should hold these values and the description property should look like this:

"red: 86.0, green: 191.0, blue: 131.0, alpha: 1.0"

Note: Init methods typically list parameters in the same order of property declaration. For this task, stick to the order red,green,blue,alpha.

I dont quite understand what the task wants me to to with the constant description. Thought I should return the value as the description string, but I get som syntax errors it seems.

need some help on this one :) Thanks in advanced.

struct RGBColor {
    let red: Double
    let green: Double
    let blue: Double
    let alpha: Double

    let description: String

    // Add your code below
    init(red: Double, green: Double, blue: Double, alpha: Double) {

        self.red = red
        self.green = green
        self.blue = blue
        self.alpha = alpha



    }
    return description("red: \(red), green: \(green), blue: \(blue), alpha:\(alpha)")
}