Prevent loading of duplicate resources

[slavafomin]

Hello!

As far as I can see, this service will add any specified resource every time the method is called, even if that resource was already added.

Maybe we should ignore "duplicate" calls and just fire the promise immediately?

[urish]

@slavafomin sounds good. Can you please create a pull-request for this?

[slavafomin]

Thanks )
I will do this if time permits )

[urish]

Thank you!

You can find here some information about the project structure and how to set up your environment.