public void TestPrevAll()
{
var n1 = new HText("Content 1");
var n2 = new HElement("span", "Content 2");
var n3 = new HElement("span", "Content 3");
var n4 = new HText("Content 4");
var element = new HElement("div", n1, n2, n3, n4);
Assert.Equal(new HNode[] { n2, n1 }, n3.PrevAll().ToArray());
Assert.Equal(new HNode[] { n2, n1, n3 }, new HNode[] { n1, n3, n4 }.PrevAll().ToArray());
Assert.Equal(new HNode[] { }, ((HNode[])null).PrevAll().ToArray());
}