public void TestConstruction1()
{
var collection = new BookmarkCollection(_bookmarks.Object, TimeSpan.Zero);
collection.Count.Should().Be(0);
collection.Bookmarks.Should().BeEmpty();
collection.Contains(null, 0).Should().BeFalse();
collection.Contains(_dataSource.Object, -1).Should().BeFalse();
collection.Contains(_dataSource.Object, 0).Should().BeFalse();
collection.Contains(_dataSource.Object, 1).Should().BeFalse();
collection.Contains(_dataSource.Object, 2).Should().BeFalse();
}