         return constraint
     }
     
-    class func topToBottom(
-        view:UIView,
-        toView:UIView,
-        constant:CGFloat = 0,
-        multiplier:CGFloat = 1) -> NSLayoutConstraint
-    {
-        let constraint:NSLayoutConstraint = NSLayoutConstraint(
-            item:view,
-            attribute:NSLayoutAttribute.top,
-            relatedBy:NSLayoutRelation.equal,
-            toItem:toView,
-            attribute:NSLayoutAttribute.bottom,
-            multiplier:1,
-            constant:constant)
-        
-        return constraint
-    }
-    
-    class func bottomToBottom(
-        view:UIView,
-        toView:UIView,
-        constant:CGFloat = 0,
-        multiplier:CGFloat = 1) -> NSLayoutConstraint
-    {
-        let constraint:NSLayoutConstraint = NSLayoutConstraint(
-            item:view,
-            attribute:NSLayoutAttribute.bottom,
-            relatedBy:NSLayoutRelation.equal,
-            toItem:toView,
-            attribute:NSLayoutAttribute.bottom,
-            multiplier:1,
-            constant:constant)
-        
-        return constraint
-    }
-    
-    class func bottomToTop(
-        view:UIView,
-        toView:UIView,
-        constant:CGFloat = 0,
-        multiplier:CGFloat = 1) -> NSLayoutConstraint
-    {
-        let constraint:NSLayoutConstraint = NSLayoutConstraint(
-            item:view,
-            attribute:NSLayoutAttribute.bottom,
-            relatedBy:NSLayoutRelation.equal,
-            toItem:toView,
-            attribute:NSLayoutAttribute.top,
-            multiplier:1,
-            constant:constant)
-        
-        return constraint
-    }
-    
-    class func leftToLeft(
-        view:UIView,
-        toView:UIView,
-        constant:CGFloat = 0,
-        multiplier:CGFloat = 1) -> NSLayoutConstraint
-    {
-        let constraint:NSLayoutConstraint = NSLayoutConstraint(
-            item:view,
-            attribute:NSLayoutAttribute.left,
-            relatedBy:NSLayoutRelation.equal,
-            toItem:toView,
-            attribute:NSLayoutAttribute.left,
-            multiplier:1,
-            constant:constant)
-        
-        return constraint
-    }
-    
-    class func leftToRight(
+    @discardableResult class func topToBottom(
+        view:UIView,
+        toView:UIView,
+        constant:CGFloat = 0,
+        multiplier:CGFloat = 1) -> NSLayoutConstraint
+    {
+        let constraint:NSLayoutConstraint = NSLayoutConstraint(
+            item:view,
+            attribute:NSLayoutAttribute.top,
+            relatedBy:NSLayoutRelation.equal,
+            toItem:toView,
+            attribute:NSLayoutAttribute.bottom,
+            multiplier:1,
+            constant:constant)
+        constraint.isActive = true
+        
+        return constraint
+    }
+    
+    @discardableResult class func bottomToBottom(
+        view:UIView,
+        toView:UIView,
+        constant:CGFloat = 0,
+        multiplier:CGFloat = 1) -> NSLayoutConstraint
+    {
+        let constraint:NSLayoutConstraint = NSLayoutConstraint(
+            item:view,
+            attribute:NSLayoutAttribute.bottom,
+            relatedBy:NSLayoutRelation.equal,
+            toItem:toView,
+            attribute:NSLayoutAttribute.bottom,
+            multiplier:1,
+            constant:constant)
+        constraint.isActive = true
+        
+        return constraint
+    }
+    
+    @discardableResult class func bottomToTop(
+        view:UIView,
+        toView:UIView,
+        constant:CGFloat = 0,
+        multiplier:CGFloat = 1) -> NSLayoutConstraint
+    {
+        let constraint:NSLayoutConstraint = NSLayoutConstraint(
+            item:view,
+            attribute:NSLayoutAttribute.bottom,
+            relatedBy:NSLayoutRelation.equal,
+            toItem:toView,
+            attribute:NSLayoutAttribute.top,
+            multiplier:1,
+            constant:constant)
+        constraint.isActive = true
+        
+        return constraint
+    }
+    
+    @discardableResult class func leftToLeft(
+        view:UIView,
+        toView:UIView,
+        constant:CGFloat = 0,
+        multiplier:CGFloat = 1) -> NSLayoutConstraint
+    {
+        let constraint:NSLayoutConstraint = NSLayoutConstraint(
+            item:view,
+            attribute:NSLayoutAttribute.left,
+            relatedBy:NSLayoutRelation.equal,
+            toItem:toView,
+            attribute:NSLayoutAttribute.left,
+            multiplier:1,
+            constant:constant)
+        constraint.isActive = true
+        
+        return constraint
+    }
+    
+    @discardableResult class func leftToRight(
         view:UIView,
         toView:UIView,
         constant:CGFloat = 0,

            attribute:NSLayoutAttribute.height,
            multiplier:1,
            constant:0)
        
        return constraint
    }
    
    class func equals(view:UIView, toView:UIView, margin:CGFloat = 0) -> [NSLayoutConstraint]
    {
        let top:NSLayoutConstraint = NSLayoutConstraint.topToTop(
            view:view,
            toView:toView,
            constant:margin)
        let bottom:NSLayoutConstraint = NSLayoutConstraint.bottomToBottom(
            view:view,
            toView:toView,
            constant:-margin)
        let left:NSLayoutConstraint = NSLayoutConstraint.leftToLeft(
            view:view,
            toView:toView,
            constant:margin)
        let right:NSLayoutConstraint = NSLayoutConstraint.rightToRight(
            view:view,
            toView:toView,
            constant:-margin)
        
        let constraints:[NSLayoutConstraint] = [
            top,
            bottom,
            left,
            right
        ]
        
        return constraints
    }
    
    class func equalsHorizontal(view:UIView, toView:UIView, margin:CGFloat = 0) -> [NSLayoutConstraint]
    {
        let left:NSLayoutConstraint = NSLayoutConstraint.leftToLeft(
            view:view,
            toView:toView,
            constant:margin)
        let right:NSLayoutConstraint = NSLayoutConstraint.rightToRight(
            view:view,
            toView:toView,
            constant:-margin)
        
        let constraints:[NSLayoutConstraint] = [
            left,
            right
        ]
        
        return constraints
    }
    class func equalsVertical(view:UIView, toView:UIView, margin:CGFloat = 0) -> [NSLayoutConstraint]
    {
        let top:NSLayoutConstraint = NSLayoutConstraint.topToTop(
            view:view,
            toView:toView,
            constant:margin)
        let bottom:NSLayoutConstraint = NSLayoutConstraint.bottomToBottom(
            view:view,
            toView:toView,
            constant:-margin)
        
        let constraints:[NSLayoutConstraint] = [
            top,
            bottom
        ]
        
        return constraints
    }
}

            attribute:NSLayoutAttribute.right,
            multiplier:multiplier,
            constant:constant)
        constraint.isActive = true
        
        return constraint
    }
    
    @discardableResult class func rightToRight(
        view:UIView,
        toView:UIView,
        constant:CGFloat = 0,
        multiplier:CGFloat = 1) -> NSLayoutConstraint
    {
        let constraint:NSLayoutConstraint = NSLayoutConstraint(
            item:view,
            attribute:NSLayoutAttribute.right,
            relatedBy:NSLayoutRelation.equal,
            toItem:toView,
            attribute:NSLayoutAttribute.right,
            multiplier:1,
            constant:constant)
        constraint.isActive = true
        
        return constraint
    }
    
    @discardableResult class func rightToLeft(
        view:UIView,
        toView:UIView,
        constant:CGFloat = 0,
        multiplier:CGFloat = 1) -> NSLayoutConstraint
    {
        let constraint:NSLayoutConstraint = NSLayoutConstraint(
            item:view,
            attribute:NSLayoutAttribute.right,
            relatedBy:NSLayoutRelation.equal,
            toItem:toView,
            attribute:NSLayoutAttribute.left,
            multiplier:1,
            constant:constant)
        constraint.isActive = true
        
        return constraint
    }
    
    @discardableResult class func width(
        view:UIView,
        constant:CGFloat = 0,
        multiplier:CGFloat = 1) -> NSLayoutConstraint
