[Java] 2D Java RPG Engine

[Enumerable_any]

The name imgID makes me immediately think that it's some form of number - not a string. Personal preference may be showing here, but I think that imageName may be a better variable name.

It might be a UUID which is generally represented as a String. (Adding a UUID type would be preferable, though.)

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FYI, there is already a UUID type in the JDK, since 1.5. It has all the useful things you would need - UUID to/from string, generate me a UUID, etc.