CodeIgniter - A function for several controllers

I'm using CI in my projects, but I have a question. I have several controllers that need to access the same api, I currently create the connection with a function called "apicall" in all controllers, and hence I use it with $ this-> apicall, what I need is to optimize this by doing this apicall function not only it, but several others that happens the same thing) be created only once, and be able to use it in other controllers. Is it possible to do this in IC?