code: private static boolean has2DCoordinates(List<IBond> bonds) {
          for (IBond bond : bonds) {
              if (bond.getBegin().getPoint2d() == null || bond.getEnd().getPoint2d() == null) return false;
          }
          return true;
      }
docs: Check if all atoms in the bond list have 2D coordinates. There is some
  redundant checking but the list will typically be short.
  
  @param bonds the bonds to check
  @return whether all atoms have 2D coordinates