Dealing with methods of same name but different parameters

[RevealedSoulEven]

System.Void InitiatePurchase(System.String productId); // 0x01ae5404
System.Void InitiatePurchase(UnityEngine.Purchasing.Product product, System.String developerPayload); // 0x01ae55e0
System.Void InitiatePurchase(System.String purchasableId, System.String developerPayload); // 0x01ae5468

I want to implement anyone of them and then invoke them too. How can I do it?

[thinhbuzz]

Use overload, eg:
method('InitiatePurchase').overload(System.String')

[RevealedSoulEven]

Thanks a lot. What about multiple parametric functions?