private static async ValueTask <ISingletonFileSystem> TestFileSystem()
{
var fileSystem = new MemoryFileSystem(new NullFileEventService());
var root = await fileSystem.CreateFileHandle(Url.Parse("file://test/"));
var foo = await fileSystem.CreateDirectory(root, "foo");
var bar = await fileSystem.CreateDirectory(foo, "bar");
var dir = await fileSystem.CreateDirectory(bar, "dir");
await fileSystem.CreateFile(bar, "a", Convert.FromHexString("010203"));
await fileSystem.CreateFile(bar, "b", Convert.FromHexString("010203"));
await fileSystem.CreateFile(bar, "c", Convert.FromHexString("010203"));
await fileSystem.CreateFile(dir, "a", Convert.FromHexString("010203"));
await fileSystem.CreateFile(dir, "b", Convert.FromHexString("010203"));
return(fileSystem);
}