GeneralTreeExtensions ToTree Method Children Support Sorting.

[Fact]
public void ToTreeOrderBy_Test()
{
	var regions = new List<Regin>
	{
		new Regin
		{
			Id = 1,
			Name = "b北京"
		},
		new Regin
		{
			Id = 2,
			Name = "b东城区",
			ParentId = 1
		},
		new Regin
		{
			Id = 3,
			Name = "a西城区",
			ParentId = 1
		},
		new Regin
		{
			Id = 4,
			Name = "a河北"
		},
		new Regin
		{
			Id = 5,
			Name = "b石家庄",
			ParentId = 4
		},
		new Regin
		{
			Id = 6,
			Name = "a承德",
			ParentId = 4
		},
		new Regin
		{
			Id = 7,
			Name = "b双桥区",
			ParentId = 6
		},
		new Regin
		{
			Id = 8,
			Name = "a双滦区",
			ParentId = 6
		}
	};

	var tree = regions.ToTreeOrderBy<Regin, long, string>(x => x.Name).ToList();

	tree.First().Name.ShouldBe("a河北");
	tree.First().Children.First().Name.ShouldBe("a承德");
	tree.First().Children.First().Children.First().Name.ShouldBe("a双滦区");
}