     
     // MARK: Properties
     
+    private let gpios: [GPIO]
     private let agpio: GPIO
     private let bgpio: GPIO
     private let cgpio: GPIO

    // MARK: Public methods
    
    func displayDigit(_ digit: Digit) {
        switch digit {
        default:
            switchSegment(.a, to: 1)
        }
    }
    
    
}

            fatalError("There should be 7 gpios for the one digit segment display")
        }
        
        self.gpios = gpios
        self.agpio = gpios[0]
        self.bgpio = gpios[1]
        self.cgpio = gpios[2]
