         fatalError("init(coder:) has not been implemented")
     }
     
+    /**
+     Manage generating constraints.
+     
+     */
     private func generateConstraints() {
         
         self.generateMessageViewConstraints()

        layoutIfNeeded()
    }
    
    func removeHud(animated: Bool, onDone: ((Void) -> Void)?) {
        
        NotificationCenter.default.removeObserver(self)

extension HudView {
    
    /**
     Creates a HUD view according the appearance struct.
     
     */
    static func create() -> HudView {
