An extension for UILabel to set text with specific kerning, line spacing or line height multiple

UILabel+Spacing.swift

import UIKit

extension UILabel {

    func setText(text: String, withKerning kerning: Double) {
        self.attributedText = NSAttributedString(string: text, attributes: kerningAttribute(kerning))
    }
    
    func setText(text: String, withLineSpacing lineSpacing: CGFloat) {
        self.attributedText = NSAttributedString(string: text, attributes: lineSpacingAttribute(lineSpacing))
    }
    
    func setText(text: String, withLineHeightMultiple lineHeightMultiple: CGFloat) {
        self.attributedText = NSAttributedString(string: text, attributes:lineHeightMultipleAttribute(lineHeightMultiple))
    }
    
    func setText(text: String, withKerning kerning: Double, lineSpacing: CGFloat) {
        var attributes = kerningAttribute(kerning)
        attributes.add(lineSpacingAttribute(lineSpacing))
        self.attributedText = NSAttributedString(string: text, attributes: attributes)
    }
    
    func setText(text: String, withKerning kerning: Double, lineHeightMultiple: CGFloat) {
        var attributes = kerningAttribute(kerning)
        attributes.add(lineHeightMultipleAttribute(lineHeightMultiple))
        self.attributedText = NSAttributedString(string: text, attributes: attributes)
    }
    
    
    
    private func kerningAttribute(kerning: Double) -> [String: AnyObject] {
        return [NSKernAttributeName: kerning]
    }
    
    private func lineSpacingAttribute(lineSpacing: CGFloat) -> [String: AnyObject] {
        let paragraphStyle = NSMutableParagraphStyle()
        paragraphStyle.lineSpacing = lineSpacing
        return [NSParagraphStyleAttributeName : paragraphStyle]
    }
    
    private func lineHeightMultipleAttribute(lineHeightMultiple: CGFloat) -> [String: AnyObject] {
        let paragraphStyle = NSMutableParagraphStyle()
        paragraphStyle.lineHeightMultiple = lineHeightMultiple
        return [NSParagraphStyleAttributeName : paragraphStyle]
    }
}


private extension Dictionary {
    mutating func add(dictionary: Dictionary) {
        for (name, value) in dictionary {
            self[name] = value
        }
    }
}