docs: public List<Assignment> getNonzeroAssignments() {
      Iterator<Outcome> outcomeIter = outcomeIterator();
      List<Assignment> assignments = Lists.newArrayList();
      while (outcomeIter.hasNext()) {
        Outcome outcome = outcomeIter.next();
        if (outcome.getProbability() != 0.0) {
          assignments.add(outcome.getAssignment());
        }
      }
      return assignments;
    }