code: @Override
      public StereoEncoder create(IAtomContainer container, int[][] graph) {
  
          // index atoms for quick lookup - wish we didn't have to do this
          // but the it's better than calling getAtomNumber every time - we use
          // a lazy creation so it's only created if there was a need for it
          Map<IAtom, Integer> atomToIndex = null;
  
          List<StereoEncoder> encoders = new ArrayList<StereoEncoder>();
  
          // for each double-bond element - create a new encoder
          for (IStereoElement se : container.stereoElements()) {
              if (se instanceof IDoubleBondStereochemistry) {
                  encoders.add(encoder((IDoubleBondStereochemistry) se, atomToIndex = indexMap(atomToIndex, container),
                          graph));
              }
          }
  
          return encoders.isEmpty() ? StereoEncoder.EMPTY : new MultiStereoEncoder(encoders);
      }
docs: {@inheritDoc}