Consider this class:
public class Content
{
public virtual bool IsCheckedOut {get; private set;}
public virtual void CheckOut()
{
IsChec
why don't you simply set up the content to be checked out to start with? Remember, you are only testing the behaviour of the CheckIn function.
[TestMethod]
public void CheckInSetsCheckedOutStatusToFalse()
{
// arrange - create a checked out item
Content c = new Content();
c.CheckOut();
// act - check it in
c.CheckIn();
// assert - IsCheckedOut should be set back to false
Assert.AreEqual(false, c.IsCheckedOut);
}