public void AddColumns() { Column[] columns = new Column[] { new Column("Name", ColumnType.String), new Column("Age", ColumnType.Integer) }; Set set = new Set(columns); NameValues values = new NameValues(); values.Add("Name", "Adam"); values.Add("Age", 800); set = set.AddTuple(values); Column[] newcolumns = new Column[] { new Column("Height", ColumnType.Integer), new Column("Weight", ColumnType.Integer) }; var result = set.AddColumns(newcolumns); Assert.AreNotEqual(result, set); Assert.IsNotNull(result.Tuples); Assert.AreEqual(1, result.Tuples.Count()); Assert.AreEqual(4, result.Columns.Count()); Tuple tuple = result.Tuples.First(); Assert.AreEqual("Adam", tuple[0]); Assert.AreEqual(800, tuple[1]); Assert.IsNull(tuple[2]); Assert.IsNull(tuple[3]); }