code: private static ILigand[] getLigands(IAtom atom, IAtomContainer container, IAtom exclude) {
  
          List<IAtom> neighbors = container.getConnectedAtomsList(atom);
  
          ILigand[] ligands = new ILigand[neighbors.size() - 1];
  
          int i = 0;
          for (IAtom neighbor : neighbors) {
              if (!neighbor.equals(exclude)) ligands[i++] = new Ligand(container, new VisitedAtoms(), atom, neighbor);
          }
  
          return ligands;
      }
docs: Obtain the ligands connected to the 'atom' excluding 'exclude'. This is
  mainly meant as a utility for double-bond labelling.
  
  @param atom      an atom
  @param container a structure to which 'atom' belongs
  @param exclude   exclude this atom - can not be null
  @return the ligands