public void CopyToCopiesDequesContent()
{
ICollection deque = new Deque <String>(new[] { "1", "2", "3" });
var array = new String[5];
deque.CopyTo(array, 1);
Assert.Null(array[0]);
Assert.Null(array[4]);
Assert.AreEqual(array.Skip(1).Take(3), deque.Cast <String>());
}