code: public void updateSubTerm() {
          if (subTerms.size() == 1) {
              // if there is only one subterm, it is necessary to update
              final IndexTerm term = subTerms.get(0); // get the only subterm
              if (term.getTermPrefix() == IndexTermPrefix.SEE) {
                  //if the only subterm is index-see update it to index-see-also
                  term.setTermPrefix(IndexTermPrefix.SEE_ALSO);
              }
  //            subTerms.set(0, term);
          }
      }
docs: Update the sub-term prefix from "See also" to "See" if there is only one sub-term.