Error trying to extend InputComponent file

I’m trying to understand how InputController works and i got the hang of it recently, as much as i decided to implement a little function to the source code of the ortiginal component. i added a GetActionBindings which returns the array of ActionBindings (because it is a private field) and nothis has exploded. However, if i call the function, i come across to a compile error: “External symbol reference not found-yadda-yadda”. What should i do? Am i missing something? my goal is to know how the engine works, and how i can use it as my will.