code: void invert(Collection<AtomPair> pairs) {
          for (AtomPair pair : pairs) {
              if (congestion.contribution(pair.fst, pair.snd) < MIN_SCORE)
                  continue;
              if (fusionPointInversion(pair))
                  continue;
              if (macroCycleInversion(pair))
                  continue;
          }
      }
docs: Special case congestion minimisation, rotate terminals bonds around ring
  systems so they are inside the ring.
  
  @param pairs congested atom pairs