public void RowKeys_and_Column_Keys_should_be_correct()
 {
     var b = new Vector<Tuple<int, int>, int>
     {
         {new Tuple<int, int>(0, 0), 1},
         {new Tuple<int, int>(2, 1), -1},
         {new Tuple<int, int>(0, 1), 2},
         {new Tuple<int, int>(0, 2), 1}
     };
     b.ColumnKeys().ShouldNumber(3);
     b.RowKeys().ShouldNumber(2);
     b.Width().ShouldEqual(3);
     b.Height().ShouldEqual(3);
 }