public void ChildColumns()
{
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);
// ChildColumns 1
Assert.Equal(1, dRel.ChildColumns.Length);
// ChildColumns 2
Assert.Equal(dtChild.Columns[0], dRel.ChildColumns[0]);
}