public void ParentColumns()
{
var ds = new DataSet();
DataTable dtChild = DataProvider.CreateChildDataTable();
DataTable dtParent = DataProvider.CreateParentDataTable();
ds.Tables.Add(dtParent);
ds.Tables.Add(dtChild);
DataRelation dRel;
dRel = new DataRelation("MyRelation", dtParent.Columns[0], dtChild.Columns[0]);
ds.Relations.Add(dRel);
// ParentColumns 1
Assert.Equal(1, dRel.ParentColumns.Length);
// ParentColumns 2
Assert.Equal(dtParent.Columns[0], dRel.ParentColumns[0]);
}