How to use one codeigniter instance across multiple libraries

[eluser]Unknown[/eluser]
Hi guys,

I am working on a large codeigniter affiliate system application. This application is requiring me to me to use multiple custom libraries which extend from a main class.

for example

class Click extends Tracking {
}

class Click_Commissions extends Click {
}


At the moment I am creating a ci instance in the construct of each class however as I sometimes load multiple libraries from inside one library I end up with quite a few ci instances...does anybody have any idea what the best way to use one ci instance would be instead of calling the instance multiple times?

Thanks

Paul