static S[] conceptFields_drop = {"className", "fieldValues", "id", "created", "refs", "backRefs", "_concepts"};

static Set<S> conceptFields(Concept c) {
  ret setMinus(mergeSets(allNonStaticFields(c), keys(c.fieldValues)), conceptFields_drop);
}

static Set<S> conceptFields(Class<? extends Concept> c) {
  ret setMinus(allNonStaticFields(c), conceptFields_drop);
}