public ConstraintTest()
{
//Setup DataTable
_table = new DataTable("TestTable");
_table.Columns.Add("Col1", typeof(int));
_table.Columns.Add("Col2", typeof(int));
//Use UniqueConstraint to test Constraint Base Class
_constraint1 = new UniqueConstraint(_table.Columns[0], false);
_constraint2 = new UniqueConstraint(_table.Columns[1], false);
// not sure why this is needed since a new _table was just created
// for us, but this Clear() keeps the tests from throwing
// an exception when the Add() is called.
_table.Constraints.Clear();
}