code: public List<Pair<A, B>> getEntries() {
          List<Pair<A, B>> l = new ArrayList<>(size());
          for (Map.Entry<A, B> x : map1.entrySet())
              l.add(new Pair<>(x.getKey(), x.getValue()));
          return l;
      }
docs: Returns a new List with all the entries in this bimap