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

        
    }
    
    func addHeightConstraint(relation relation1: NSLayoutRelation, constant: CGFloat) -> NSLayoutConstraint {
        
        return self.addHeightConstraint(toView: nil, relation: relation1, constant: constant)
    }

    
    // MARK: - Center Y Constraint
    
    public func addCenterYConstraint(toView view: UIView?) -> NSLayoutConstraint {
        
        return self.addCenterYConstraint(toView: view, relation: .Equal, constant: 0)
    }
    
    public func addCenterYConstraint(toView view: UIView?, constant: CGFloat) -> NSLayoutConstraint {
        
        return self.addCenterYConstraint(toView: view, relation: .Equal, constant: constant)
    }
    
    public 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)
