     
     // MARK: Attributes
 
+    /**
+     Applies constraints to the receiver with attributes `attributes` all
+     equal to its superview.
+     */
     func makeAttributesEqualToSuperview(_ attributes: [NSLayoutAttribute], offset: CGFloat = 0) {
         guard let superview = superview else {
             return

                                                   constant: constant))
    }
    
    func makeAttribute(_ attribute: NSLayoutAttribute, equalToOtherView otherView: UIView, attribute otherAttribute: NSLayoutAttribute, constant: CGFloat = 0) {
        guard let sv = otherView.superview,
            sv == self.superview else {
                return

        }
    }

    /**
     Applies a constraint to the receiver with attribute `attribute` and
     the specified constant.
     */
    func makeAttribute(_ attribute: NSLayoutAttribute, equalTo constant: CGFloat) {
        guard let superview = superview else {
            return
