public void IsDone_LastElement_ReturnsTrue()
 {
     for (int i = 0; i < Constants.NumberOfCellsInSegment; i++)
     {
         _iterator.Next();
     }
     Assert.IsTrue(_iterator.IsDone());
 }
 public void Next_IteratesThroughColumn_HasExpected(int column, int [] columnValues)
 {
     _iterator = new ColumnIterator(_puzzle, column);
     foreach (int value in columnValues)
     {
         Assert.AreEqual(value, _iterator.GetCurrent().Value);
         if (!_iterator.IsDone())
         {
             _iterator.Next();
         }
     }
 }