diff --git a/TZStackViewTests/TZStackViewTests.swift b/TZStackViewTests/TZStackViewTests.swift
index 0d099c8..0df1820 100644
--- a/TZStackViewTests/TZStackViewTests.swift
+++ b/TZStackViewTests/TZStackViewTests.swift
@@ -1054,4 +1054,205 @@ class TZStackViewTests: TZStackViewTestCase {
 
         verifyArrangedSubviewConsistency()
     }
+    
+    // If you are not animating the hidden property, the hidden property should be set immediately
+    func testNonAnimatingHidden() {
+        let uiTestView = uiStackView.arrangedSubviews.last!
+        let tzTestView = tzStackView.arrangedSubviews.last!
+        
+        let expectation = expectationWithDescription("delay")
+        
+        dispatch_after(dispatch_time(DISPATCH_TIME_NOW, Int64(1 * Double(NSEC_PER_SEC))), dispatch_get_main_queue()) {
+            uiTestView.hidden = true
+            tzTestView.hidden = true
+            
+            XCTAssert(uiTestView.hidden)
+            XCTAssert(tzTestView.hidden)
+            XCTAssert(uiTestView.layer.hidden)
+            XCTAssert(tzTestView.layer.hidden)
+        }
+        
+        dispatch_after(dispatch_time(DISPATCH_TIME_NOW, Int64(1.2 * Double(NSEC_PER_SEC))), dispatch_get_main_queue()) {
+            expectation.fulfill()
+        }
+        
+        waitForExpectationsWithTimeout(100, handler: nil)
+    }
+    
+    // If you are not animating the hidden property, the hidden property should be set immediately
+    func testNonAnimatingHiddenWithOther() {
+        let uiTestView = uiStackView.arrangedSubviews.last!
+        let tzTestView = tzStackView.arrangedSubviews.last!
+        
+        let expectation = expectationWithDescription("delay")
+        
+        uiTestView.backgroundColor = UIColor.clearColor()
+        tzTestView.backgroundColor = UIColor.clearColor()
+        UIView.animateWithDuration(2) {
+            uiTestView.backgroundColor = UIColor.greenColor()
+            tzTestView.backgroundColor = UIColor.greenColor()
+        }
+        
+        dispatch_after(dispatch_time(DISPATCH_TIME_NOW, Int64(1 * Double(NSEC_PER_SEC))), dispatch_get_main_queue()) {
+            uiTestView.hidden = true
+            tzTestView.hidden = true
+            
+            XCTAssert(uiTestView.hidden)
+            XCTAssert(tzTestView.hidden)
+            XCTAssert(uiTestView.layer.hidden)
+            XCTAssert(tzTestView.layer.hidden)
+        }
+        
+        dispatch_after(dispatch_time(DISPATCH_TIME_NOW, Int64(1.2 * Double(NSEC_PER_SEC))), dispatch_get_main_queue()) {
+            expectation.fulfill()
+        }
+        
+        waitForExpectationsWithTimeout(100, handler: nil)
+    }
+    
+    func testAnimatingHidden() {
+        let uiTestView = uiStackView.arrangedSubviews.last!
+        let tzTestView = tzStackView.arrangedSubviews.last!
+        
+        let expectation = expectationWithDescription("delay")
+        
+        UIView.animateWithDuration(1) {
+            uiTestView.hidden = true
+            tzTestView.hidden = true
+            
+            // Note uiTestView.hidden == true, tzTestView.hidden == false
+            
+            // The presentation should not be hidden.
+            XCTAssert(!uiTestView.layer.hidden)
+            XCTAssert(!tzTestView.layer.hidden)
+        }
+        
+        dispatch_after(dispatch_time(DISPATCH_TIME_NOW, Int64(1.2 * Double(NSEC_PER_SEC))), dispatch_get_main_queue()) {
+            XCTAssert(uiTestView.hidden)
+            XCTAssert(tzTestView.hidden)
+            XCTAssert(uiTestView.layer.hidden)
+            XCTAssert(tzTestView.layer.hidden)
+        }
+        
+        dispatch_after(dispatch_time(DISPATCH_TIME_NOW, Int64(1.4 * Double(NSEC_PER_SEC))), dispatch_get_main_queue()) {
+            expectation.fulfill()
+        }
+        
+        waitForExpectationsWithTimeout(100, handler: nil)
+    }
+    
+    func testAnimatingHiddenWithOther() {
+        let uiTestView = uiStackView.arrangedSubviews.last!
+        let tzTestView = tzStackView.arrangedSubviews.last!
+        
+        let expectation = expectationWithDescription("delay")
+        
+        UIView.animateWithDuration(1) {
+            uiTestView.hidden = true
+            tzTestView.hidden = true
+        }
+        
+        uiTestView.backgroundColor = UIColor.clearColor()
+        tzTestView.backgroundColor = UIColor.clearColor()
+        UIView.animateWithDuration(2) {
+            uiTestView.backgroundColor = UIColor.greenColor()
+            tzTestView.backgroundColor = UIColor.greenColor()
+        }
+        
+        dispatch_after(dispatch_time(DISPATCH_TIME_NOW, Int64(1.2 * Double(NSEC_PER_SEC))), dispatch_get_main_queue()) {
+            // The view should be hidden after the hiding animation completes even if there are still other animations
+            XCTAssert(uiTestView.hidden)
+            XCTAssert(tzTestView.hidden)
+            XCTAssert(uiTestView.layer.hidden)
+            XCTAssert(tzTestView.layer.hidden)
+        }
+        
+        dispatch_after(dispatch_time(DISPATCH_TIME_NOW, Int64(2.2 * Double(NSEC_PER_SEC))), dispatch_get_main_queue()) {
+            expectation.fulfill()
+        }
+        
+        waitForExpectationsWithTimeout(100, handler: nil)
+    }
+    
+    // The completion callback of an animation should be called
+    func testHidingAnimationCallback() {
+        let uiTestView = uiStackView.arrangedSubviews.last!
+        let tzTestView = tzStackView.arrangedSubviews.last!
+        
+        let expectation = expectationWithDescription("delay")
+        
+        var uiCompletionCalled = false
+        var tzCompletionCalled = false
+        
+        UIView.animateWithDuration(1,
+            animations: {
+                uiTestView.hidden = true
+            }, completion: { _ in
+                uiCompletionCalled = true
+        })
+        
+        UIView.animateWithDuration(1,
+            animations: {
+                tzTestView.hidden = true
+            }, completion: { _ in
+                tzCompletionCalled = true
+        })
+        
+        dispatch_after(dispatch_time(DISPATCH_TIME_NOW, Int64(1.2 * Double(NSEC_PER_SEC))), dispatch_get_main_queue()) {
+            XCTAssert(uiCompletionCalled)
+            XCTAssert(tzCompletionCalled)
+        }
+        
+        dispatch_after(dispatch_time(DISPATCH_TIME_NOW, Int64(1.4 * Double(NSEC_PER_SEC))), dispatch_get_main_queue()) {
+            expectation.fulfill()
+        }
+        
+        waitForExpectationsWithTimeout(100, handler: nil)
+    }
+    
+    // The completion callback of an animation should be called when the animation is canceled
+    func testHidingAnimationCallbackCancel() {
+        let uiTestView = uiStackView.arrangedSubviews.last!
+        let tzTestView = tzStackView.arrangedSubviews.last!
+        
+        let expectation = expectationWithDescription("delay")
+        
+        var uiCompletionCalled = false
+        var tzCompletionCalled = false
+        
+        UIView.animateWithDuration(1,
+            animations: {
+                uiTestView.hidden = true
+            }, completion: { finished in
+                uiCompletionCalled = true
+                XCTAssert(!finished)
+        })
+        
+        UIView.animateWithDuration(1,
+            animations: {
+                tzTestView.hidden = true
+            }, completion: { finished in
+                tzCompletionCalled = true
+                XCTAssert(!finished)
+        })
+        
+        dispatch_after(dispatch_time(DISPATCH_TIME_NOW, Int64(0.5 * Double(NSEC_PER_SEC))), dispatch_get_main_queue()) {
+            // this will cancel the animation
+            self.uiStackView.removeFromSuperview()
+            self.tzStackView.removeFromSuperview()
+        }
+        
+        dispatch_after(dispatch_time(DISPATCH_TIME_NOW, Int64(0.7 * Double(NSEC_PER_SEC))), dispatch_get_main_queue()) {
+            XCTAssert(uiCompletionCalled)
+            XCTAssert(tzCompletionCalled)
+            XCTAssert(uiTestView.hidden)
+            XCTAssert(tzTestView.hidden)
+        }
+        
+        dispatch_after(dispatch_time(DISPATCH_TIME_NOW, Int64(1.4 * Double(NSEC_PER_SEC))), dispatch_get_main_queue()) {
+            expectation.fulfill()
+        }
+        
+        waitForExpectationsWithTimeout(100, handler: nil)
+    }
 }