Exmaple of mocking HTTP activity

Hi,

I'm trying to write some services for interacting with REST endpoints. My
service classes use URLLoader and URLRequest internally, and seems to be
working fine.

however i am having trouble figuring out how i can test my service as the
loader and request are used internally. Im sure I'm doing something wrong,
so i was hoping someone could point me towards an example/tutorial of how to
go about this "the right way" so to speak.

Thanks in advance

Chris