     }
     
     /// Handler which handles event when keyboard will disappear
-    private var hideHandler : CompletionHandler {
+    private var hideHandler : EmptyCompletionHandler {
         get {
-            if let value = objc_getAssociatedObject(self, &AssociatedKeys.HideHandler) as? CompletionHandler
+            if let value = objc_getAssociatedObject(self, &AssociatedKeys.HideHandler) as? EmptyCompletionHandler
             {
                 return value
             }

import UIKit

/// Completion handler without parameters
public typealias CompletionHandler = () -> Void

/// Completion handler with one numerical parameter
public typealias CompletionNumberHandler = (CGFloat) -> Void

    ///   - additionalOffset: Additional offset if we don't want a keyboard to be sticked to a text field or to a text view
    open func hcChangeConstraintsConstantBasedOnKeyboardAnimatingPosition(constraints:NSLayoutConstraint..., changeConstraintConstantExactlyBasedOnMoveValue:Bool = false, additionalOffset:CGFloat = 0.0)
    {
        self.hcSetKeyboardListener(onAppear: { moveValue, keyboardHeight in
            for constraint in constraints
            {
                constraint.constant = changeConstraintConstantExactlyBasedOnMoveValue ? moveValue + additionalOffset : keyboardHeight + additionalOffset
