Why UnitType is not enum?

[Panagiotis Peikidis]

Is there any reason why the class UnitType is not an enum? Seems to me
that it is a perfect candidate for an enum.. I created a wrapper for
my project..

public enum MyType {
....
TERRAN_SCV(UnitType.TERRAN_SCV);

private UnitType type;
private MyType(UnitType type) {
this.type = type;
}
}