code: public boolean cyclic(IBond bond) {
          // XXX: linear search - but okay for now
          int u = container.indexOf(bond.getBegin());
          int v = container.indexOf(bond.getEnd());
          if (u < 0 || v < 0) throw new NoSuchElementException("atoms of the bond are not found in the container");
          return searcher.cyclic(u, v);
      }
docs: Determine whether the bond is cyclic. Note this currently requires a
  linear search to look-up the indices of each atoms.
  
  @param bond a bond of the container
  @return whether the vertex at the given index is in a cycle