public void TestToString()
{
DataColumn dc;
string sColName, sExp;
dc = new DataColumn();
//ToString = ColumnName
sColName = "Test1";
dc.ColumnName = sColName;
// ToString - ColumnName
Assert.Equal(sColName, dc.ToString());
//TosTring = ColumnName + " + " + Expression
sExp = "Tax * 1.234";
dc.Expression = sExp;
// TosTring=ColumnName + Expression
Assert.Equal(sColName + " + " + sExp, dc.ToString());
}