public void Add_DataColumn1()
{
DataTable dt = new DataTable();
DataColumn col = new DataColumn("col1", Type.GetType("System.String"));
dt.Columns.Add(col);
Assert.Equal(1, dt.Columns.Count);
Assert.Equal("col1", dt.Columns[0].ColumnName);
Assert.Equal("System.String", dt.Columns[0].DataType.ToString());
}