diff --git a/Source/Constraint.swift b/Source/Constraint.swift
index b671494..6a91fee 100644
--- a/Source/Constraint.swift
+++ b/Source/Constraint.swift
@@ -30,7 +30,7 @@ import AppKit
 /**
  * Constraint is a single item that defines all the properties for a single ConstraintMaker chain
  */
-public class Constraint {
+final public class Constraint {
     public var left: Constraint { return self.addConstraint(ConstraintAttributes.Left) }
     public var top: Constraint { return self.addConstraint(ConstraintAttributes.Top) }
     public var right: Constraint { return self.addConstraint(ConstraintAttributes.Right) }
diff --git a/Source/ConstraintItem.swift b/Source/ConstraintItem.swift
index 1c3c69d..ea811a5 100644
--- a/Source/ConstraintItem.swift
+++ b/Source/ConstraintItem.swift
@@ -30,7 +30,7 @@ import AppKit
 /**
  * ConstraintItem is a class that is used while building constraints.
  */
-public class ConstraintItem {
+final public class ConstraintItem {
     
     internal init(object: AnyObject?, attributes: ConstraintAttributes) {
         self.object = object
diff --git a/Source/ConstraintMaker.swift b/Source/ConstraintMaker.swift
index 49e03d2..c226064 100644
--- a/Source/ConstraintMaker.swift
+++ b/Source/ConstraintMaker.swift
@@ -30,7 +30,7 @@ import AppKit
 /**
  * ConstraintMaker is the maker in snap that gets all constraints kickstarted
  */
-public class ConstraintMaker {
+final public class ConstraintMaker {
     public var left: Constraint { return self.addConstraint(ConstraintAttributes.Left) }
     public var top: Constraint { return self.addConstraint(ConstraintAttributes.Top) }
     public var right: Constraint { return self.addConstraint(ConstraintAttributes.Right) }
diff --git a/Source/LayoutConstraint.swift b/Source/LayoutConstraint.swift
index 041c46e..1d92389 100644
--- a/Source/LayoutConstraint.swift
+++ b/Source/LayoutConstraint.swift
@@ -30,8 +30,8 @@ import AppKit
 /**
 * LayoutConstraint is a subclass of NSLayoutConstraint to assist Snap and also provide better debugging
 */
-public class LayoutConstraint: NSLayoutConstraint {
-    internal var constraint: Constraint?
+final public class LayoutConstraint: NSLayoutConstraint {
+    internal var snp_constraint: Constraint? = nil
 }
 
 public func ==(left: LayoutConstraint, right: LayoutConstraint) -> Bool {
diff --git a/Source/View+Snap.swift b/Source/View+Snap.swift
index 09d1bab..103e8d6 100644
--- a/Source/View+Snap.swift
+++ b/Source/View+Snap.swift
@@ -33,69 +33,69 @@ public extension View {
     
     // normal
     
-    public var snp_left: ConstraintItem { return ConstraintItem(object: self, attributes: ConstraintAttributes.Left) }
-    public var snp_top: ConstraintItem { return ConstraintItem(object: self, attributes: ConstraintAttributes.Top) }
-    public var snp_right: ConstraintItem { return ConstraintItem(object: self, attributes: ConstraintAttributes.Right) }
-    public var snp_bottom: ConstraintItem { return ConstraintItem(object: self, attributes: ConstraintAttributes.Bottom) }
-    public var snp_leading: ConstraintItem { return ConstraintItem(object: self, attributes: ConstraintAttributes.Leading) }
-    public var snp_trailing: ConstraintItem { return ConstraintItem(object: self, attributes: ConstraintAttributes.Trailing) }
-    public var snp_width: ConstraintItem { return ConstraintItem(object: self, attributes: ConstraintAttributes.Width) }
-    public var snp_height: ConstraintItem { return ConstraintItem(object: self, attributes: ConstraintAttributes.Height) }
-    public var snp_centerX: ConstraintItem { return ConstraintItem(object: self, attributes: ConstraintAttributes.CenterX) }
-    public var snp_centerY: ConstraintItem { return ConstraintItem(object: self, attributes: ConstraintAttributes.CenterY) }
-    public var snp_baseline: ConstraintItem { return ConstraintItem(object: self, attributes: ConstraintAttributes.Baseline) }
+    final public var snp_left: ConstraintItem { return ConstraintItem(object: self, attributes: ConstraintAttributes.Left) }
+    final public var snp_top: ConstraintItem { return ConstraintItem(object: self, attributes: ConstraintAttributes.Top) }
+    final public var snp_right: ConstraintItem { return ConstraintItem(object: self, attributes: ConstraintAttributes.Right) }
+    final public var snp_bottom: ConstraintItem { return ConstraintItem(object: self, attributes: ConstraintAttributes.Bottom) }
+    final public var snp_leading: ConstraintItem { return ConstraintItem(object: self, attributes: ConstraintAttributes.Leading) }
+    final public var snp_trailing: ConstraintItem { return ConstraintItem(object: self, attributes: ConstraintAttributes.Trailing) }
+    final public var snp_width: ConstraintItem { return ConstraintItem(object: self, attributes: ConstraintAttributes.Width) }
+    final public var snp_height: ConstraintItem { return ConstraintItem(object: self, attributes: ConstraintAttributes.Height) }
+    final public var snp_centerX: ConstraintItem { return ConstraintItem(object: self, attributes: ConstraintAttributes.CenterX) }
+    final public var snp_centerY: ConstraintItem { return ConstraintItem(object: self, attributes: ConstraintAttributes.CenterY) }
+    final public var snp_baseline: ConstraintItem { return ConstraintItem(object: self, attributes: ConstraintAttributes.Baseline) }
     
     #if os(iOS)
-    public var snp_firstBaseline: ConstraintItem { return ConstraintItem(object: self, attributes: ConstraintAttributes.FirstBaseline) }
-    public var snp_leftMargin: ConstraintItem { return ConstraintItem(object: self, attributes: ConstraintAttributes.LeftMargin) }
-    public var snp_rightMargin: ConstraintItem { return ConstraintItem(object: self, attributes: ConstraintAttributes.RightMargin) }
-    public var snp_topMargin: ConstraintItem { return ConstraintItem(object: self, attributes: ConstraintAttributes.TopMargin) }
-    public var snp_bottomMargin: ConstraintItem { return ConstraintItem(object: self, attributes: ConstraintAttributes.BottomMargin) }
-    public var snp_leadingMargin: ConstraintItem { return ConstraintItem(object: self, attributes: ConstraintAttributes.LeadingMargin) }
-    public var snp_trailingMargin: ConstraintItem { return ConstraintItem(object: self, attributes: ConstraintAttributes.TrailingMargin) }
-    public var snp_centerXWithinMargin: ConstraintItem { return ConstraintItem(object: self, attributes: ConstraintAttributes.CenterXWithinMargins) }
-    public var snp_centerYWithinMargin: ConstraintItem { return ConstraintItem(object: self, attributes: ConstraintAttributes.CenterYWithinMargins) }
+    final public var snp_firstBaseline: ConstraintItem { return ConstraintItem(object: self, attributes: ConstraintAttributes.FirstBaseline) }
+    final public var snp_leftMargin: ConstraintItem { return ConstraintItem(object: self, attributes: ConstraintAttributes.LeftMargin) }
+    final public var snp_rightMargin: ConstraintItem { return ConstraintItem(object: self, attributes: ConstraintAttributes.RightMargin) }
+    final public var snp_topMargin: ConstraintItem { return ConstraintItem(object: self, attributes: ConstraintAttributes.TopMargin) }
+    final public var snp_bottomMargin: ConstraintItem { return ConstraintItem(object: self, attributes: ConstraintAttributes.BottomMargin) }
+    final public var snp_leadingMargin: ConstraintItem { return ConstraintItem(object: self, attributes: ConstraintAttributes.LeadingMargin) }
+    final public var snp_trailingMargin: ConstraintItem { return ConstraintItem(object: self, attributes: ConstraintAttributes.TrailingMargin) }
+    final public var snp_centerXWithinMargin: ConstraintItem { return ConstraintItem(object: self, attributes: ConstraintAttributes.CenterXWithinMargins) }
+    final public var snp_centerYWithinMargin: ConstraintItem { return ConstraintItem(object: self, attributes: ConstraintAttributes.CenterYWithinMargins) }
     #endif
     
     // aggregates
     
-    public var snp_edges: ConstraintItem { return ConstraintItem(object: self, attributes: ConstraintAttributes.Edges) }
-    public var snp_size: ConstraintItem { return ConstraintItem(object: self, attributes: ConstraintAttributes.Size) }
-    public var snp_center: ConstraintItem { return ConstraintItem(object: self, attributes: ConstraintAttributes.Center) }
+    final public var snp_edges: ConstraintItem { return ConstraintItem(object: self, attributes: ConstraintAttributes.Edges) }
+    final public var snp_size: ConstraintItem { return ConstraintItem(object: self, attributes: ConstraintAttributes.Size) }
+    final public var snp_center: ConstraintItem { return ConstraintItem(object: self, attributes: ConstraintAttributes.Center) }
     
     #if os(iOS)
-    public var snp_margins: ConstraintItem { return ConstraintItem(object: self, attributes: ConstraintAttributes.Margins) }
-    public var snp_centerWithinMargins: ConstraintItem { return ConstraintItem(object: self, attributes: ConstraintAttributes.CenterWithinMargins) }
+    final public var snp_margins: ConstraintItem { return ConstraintItem(object: self, attributes: ConstraintAttributes.Margins) }
+    final public var snp_centerWithinMargins: ConstraintItem { return ConstraintItem(object: self, attributes: ConstraintAttributes.CenterWithinMargins) }
     #endif
     
-    public func snp_prepareConstraints(block: (make: ConstraintMaker) -> Void) -> Array<Constraint> {
+    final public func snp_prepareConstraints(block: (make: ConstraintMaker) -> Void) -> [Constraint] {
         return ConstraintMaker.prepareConstraints(self, block: block)
     }
     
-    public func snp_makeConstraints(block: (make: ConstraintMaker) -> Void) {
+    final public func snp_makeConstraints(block: (make: ConstraintMaker) -> Void) {
         ConstraintMaker.makeConstraints(self, block: block)
     }
     
-    public func snp_updateConstraints(block: (make: ConstraintMaker) -> Void) {
+    final public func snp_updateConstraints(block: (make: ConstraintMaker) -> Void) {
         ConstraintMaker.updateConstraints(self, block: block)
     }
     
-    public func snp_remakeConstraints(block: (make: ConstraintMaker) -> Void) {
+    final public func snp_remakeConstraints(block: (make: ConstraintMaker) -> Void) {
         ConstraintMaker.remakeConstraints(self, block: block)
     }
     
-    public func snp_removeConstraints() {
+    final public func snp_removeConstraints() {
         ConstraintMaker.removeConstraints(self)
     }
     
     // internal
     
-    internal var snp_installedLayoutConstraints: Array<LayoutConstraint> {
+    final internal var snp_installedLayoutConstraints: [LayoutConstraint] {
         get {
-            if let constraints = objc_getAssociatedObject(self, &installedLayoutConstraintsKey) as? Array<LayoutConstraint> {
+            if let constraints = objc_getAssociatedObject(self, &installedLayoutConstraintsKey) as? [LayoutConstraint] {
                 return constraints
             }
-            return Array<LayoutConstraint>()
+            return []
         }
         set {
             objc_setAssociatedObject(self, &installedLayoutConstraintsKey, newValue, UInt(OBJC_ASSOCIATION_RETAIN_NONATOMIC))