I know there is already some documented on this but for some odd reason a spigot thread somehow makes me feel more satisfied..anyway let's say I have a playermanager class which has two methods, addToGame and removeFromGame, all these methods do is add you to a player inventory hashmap then clears your inventory and removeFromGame restores your inventory from the hashmap and deletes the entry. Is it better practice to A. Make a static field for the hashmap and make both of the methods static. or B. Treat the hashmap as an instance variable and treat the class as singleton?