code: public List<Term> getAllTerms() {
          List<Term> ret = new ArrayList<Term>();
          ret.add(subject);
  
          List<Term> subjectTerms = subject.getTerms();
          if (subjectTerms != null) {
              ret.addAll(subjectTerms);
              for (final Term term : subjectTerms) {
                  ret.addAll(term.getAllTerms());
              }
          }
  
          if (object != null) {
              ret.addAll(object.getAllTerms());
          }
          return ret;
      }
docs: Returns a list of all terms contained by this statement's subject and
  object.
  
  @return List of terms