public void TestLoadUnload()
{
ResourceManager<string, ResourceItem>.LoadDelegate load = (string resource) => new ResourceItem (resource);
ResourceManager<string, ResourceItem>.UnloadDelegate unload = (string resource, ResourceItem item) => item = null;
var manager = new ResourceManager<string, ResourceItem> ("hello");
manager.Load = load;
manager.Unload = unload;
Assert.True (manager.Resources [0] == null);
var helloId = manager.AddReference ("hello");
Assert.True (manager.Resources [0] == null);
manager.Refresh ();
Assert.True (manager.Resources [0].Name == "hello");
manager.DecreaseReference (helloId);
Assert.True (manager.Resources [0].Name == "hello");
manager.Refresh ();
Assert.True (manager.Resources [0] == null);
}