public void Clone()
{
var clonedClauseMapping = new QuerySourceMapping();
var cloneContext = new CloneContext(clonedClauseMapping);
var clone = _resultOperator.Clone(cloneContext);
Assert.That(clone, Is.InstanceOf(typeof(UnionResultOperator)));
Assert.That(((UnionResultOperator)clone).ItemName, Is.EqualTo("itemName"));
Assert.That(((UnionResultOperator)clone).Source2, Is.SameAs(_source2));
Assert.That(((UnionResultOperator)clone).ItemType, Is.SameAs(typeof(int)));
}