     
     // MARK: - Top Constraints
     
-    func addTopConstraint(toView view: UIView?, relation: NSLayoutRelation, constant: CGFloat) -> NSLayoutConstraint {
+    public func addTopConstraint(toView view: UIView?, relation: NSLayoutRelation, constant: CGFloat) -> NSLayoutConstraint {
         
         return self.addTopConstraint(toView: view, attribute: .Top, relation: relation, constant: constant)
     }
     
-    func addTopConstraint(toView view: UIView?, attribute: NSLayoutAttribute, relation: NSLayoutRelation, constant: CGFloat) -> NSLayoutConstraint {
+    public func addTopConstraint(toView view: UIView?, attribute: NSLayoutAttribute, relation: NSLayoutRelation, constant: CGFloat) -> NSLayoutConstraint {
         
         let constraint: NSLayoutConstraint = self.createConstraint(attribute: .Top, toView: view, attribute: attribute, relation: relation, constant: constant)
         self.superview?.addConstraint(constraint)

    
    // MARK: - Center Y Constraint
    
    func addCenterYConstraint(toView view: UIView?) -> NSLayoutConstraint {
        
        return self.addCenterYConstraint(toView: view, relation: .Equal, constant: 0)
    }
    
    func addCenterYConstraint(toView view: UIView?, constant: CGFloat) -> NSLayoutConstraint {
        
        return self.addCenterYConstraint(toView: view, relation: .Equal, constant: constant)
    }
    
    func addCenterYConstraint(toView view: UIView?, relation: NSLayoutRelation, constant: CGFloat) -> NSLayoutConstraint {
        
        let constraint: NSLayoutConstraint = self.createConstraint(attribute: .CenterY, toView: view, attribute: .CenterY, relation: relation, constant: constant)
        self.superview?.addConstraint(constraint)

    
    // MARK: - Center X Constraint
    
    public func addCenterXConstraint(toView view: UIView?) -> NSLayoutConstraint {
        
        return self.addCenterXConstraint(toView: view, relation: .Equal, constant: 0)
    }
    
    public func addCenterXConstraint(toView view: UIView?, constant: CGFloat) -> NSLayoutConstraint {
        
        return self.addCenterXConstraint(toView: view, relation: .Equal, constant: constant)
    }
    
    public func addCenterXConstraint(toView view: UIView?, relation: NSLayoutRelation, constant: CGFloat) -> NSLayoutConstraint {
        
        let constraint: NSLayoutConstraint = self.createConstraint(attribute: .CenterX, toView: view, attribute: .CenterX, relation: relation, constant: constant)
        self.superview?.addConstraint(constraint)
