     public func replaceObjectsInRange(range: NSRange, withObjectsFromArray otherArray: [AnyObject], range otherRange: NSRange) { NSUnimplemented() }
     public func replaceObjectsInRange(range: NSRange, withObjectsFromArray otherArray: [AnyObject]) {
         if self.dynamicType === NSMutableArray.self {
+            _storage.reserveCapacity(count - range.length + otherArray.count)
             for var idx = 0; idx < range.length; idx++ {
                 _storage[idx + range.location] = otherArray[idx]
             }

    
    public init(capacity numItems: Int) {
        super.init(objects: nil, count: 0)
    }
    
    public required convenience init(objects: UnsafePointer<AnyObject?>, count cnt: Int) {

    }
    
    public required init(objects: UnsafePointer<AnyObject?>, count cnt: Int) {
        _storage.reserveCapacity(cnt)
        for idx in 0..<cnt {
            _storage.append(objects[idx]!)
        }
