     /// Remove an object at a given index.
     ///
     /// - Parameter index: Index.
-    func remove(at index: Int) {
+    public func remove(at index: Int) {
         guard index < count else {
             return
         }

    /// - Parameters:
    ///   - object: Object to be inserted.
    ///   - index: Index.
    func insert(_ object: AnyObject?, at index: Int) {
        guard index < count, let strongObject = object else {
            return
        }

    /// - Parameters:
    ///   - index: Index.
    ///   - object: Replacing object.
    public func replace(at index: Int, with object: AnyObject?) {
        guard index < count, let strongObject = object else {
            return
        }
