I have a qustion about empty EnumSets. I tried the .noneOf() method but i always get the "java.lang.ExceptionInInitializerError" error

Question

This is a early construct of my class:

public class Player {
    public enum Tech {
        NONE(EnumSet.noneOf(Tech.class)),
        VEGETATION(EnumSet.of(NONE)),
        LIVESTOCK(EnumSet.of(NONE)),
        STRAWBERRIES(EnumSet.of(VEGETATION)),
        BIODOME(EnumSet.of(STRAWBERRIES)),
        BIOMASS(EnumSet.of(VEGETATION, LIVESTOCK));

        private final Set<Tech> prerequisites;

        Tech(Set<Tech> prerequisites) {
            this.prerequisites = prerequisites;
        }
    }
    private Set<Tech> techsKnown;

    public Player() {
        techsKnown = EnumSet.of(Tech.NONE);
    }
}

I want NONE to have an empty Set. What would be the best way?