FPM Methods activation

Friends,

Whenever I create a a class and extend FPM Interface, do I need to activate all the methods of that class or I can only activate the method which I will be using in this class?

Technically , I would prefer to activate all the methods even though I have not used them but is there any easy way to activate all methdos in one shot instead going each method doby and activaating it?

Thanks

Krish