         )
     }
 
+    /**
+     Returns are `[a]` area unit.
+     
+     - author: Michal Konturek
+     */
     public static var are: AreaUnit {
         return AreaUnit(
             name: "are",


extension NSNumber {

    public func squareKilometer() -> Quantity {
        return Quantity(amount: self, unit: AreaUnit.squareKilometer)
    }

    public func hectare() -> Quantity {
        return Quantity(amount: self, unit: AreaUnit.hectare)
    }

    public func are() -> Quantity {
        return Quantity(amount: self, unit: AreaUnit.are)
    }

    public func squareMeter() -> Quantity {
        return Quantity(amount: self, unit: AreaUnit.squareMeter)
    }

    public func squareDecimeter() -> Quantity {
        return Quantity(amount: self, unit: AreaUnit.squareDecimeter)
    }

    public func squareCentimeter() -> Quantity {
        return Quantity(amount: self, unit: AreaUnit.squareCentimeter)
    }

    public func squareMillimeter() -> Quantity {
        return Quantity(amount: self, unit: AreaUnit.squareMillimeter)
    }

        )
    }

    /**
     Returns square centimeter `[cm²]` area unit.
     
     - author: Michal Konturek
     */
    public static var squareCentimeter: AreaUnit {
        return AreaUnit(
            name: "square centimeter",
