public void Apply_ShouldMerge(string targetXml, string transformXml, string expectedXml)
{
var targetDocument = ArrangeTargetDocument(targetXml);
var transformElement = ArrangeTransformElement(targetDocument, transformXml);
var merge = new Merge();
merge.Apply(targetDocument.DocumentElement, transformElement);
Assert.Equal(expectedXml, targetDocument.OuterXml);
}