public void UrlExtensionsTest()
{
var uri = new Uri("http://localhost/a/b/c/1.html");
string parentDirectory = UrlExtensions.GetFileDirectory(uri);
Assert.AreEqual(parentDirectory, "/a/b/c/");
var parentAddress = UrlExtensions.GetParent(uri);
Assert.AreEqual(parentAddress, "http://localhost/a/b/c/");
}