File:OnGameMethodsInitialized.png

public class MyCoolMod : IHoldfastSharedMethods, IHoldfastGame {

   // Create a static property to hold the game methods.
   public static IHoldfastGameMethods GameMethods { get; set; }

   // The game will call this method and pass in the methods object.
   public void OnGameMethodsInitialized(IHoldfastGameMethods gameMethods)
   {
       GameMethods = gameMethods;
       Debug.Log("Game methods have been initialized and stored.");
   }

   // ... rest of your IHoldfastSharedMethods implementations ...

}