private SpeedmentPredicate<ENTITY> toEntityPredicate(Predicate<E> predicate) {
        final EnumSet<E> valid = evaluate(predicate);
        switch (valid.size()) {
            case 0  : return new AlwaysFalsePredicate<>(this);
            case 1  : return new ReferenceEqualPredicate<>(this, valid.iterator().next());
            default : return new ReferenceInPredicate<>(this, valid);
        }
    }
Default implementation of the {@link EnumForeignKeyField}-interface.

@author Emil Forslund
@since  3.0.10
runtime-parent/runtime-field/src/main/java/com/speedment/runtime/field/internal/EnumForeignKeyFieldImpl.java