code: private boolean allPlaced(IRingSet rings) {
          for (int f = 0; f < rings.getAtomContainerCount(); f++) {
              if (!((IRing) rings.getAtomContainer(f)).getFlag(CDKConstants.ISPLACED)) {
                  logger.debug("allPlaced->Ring " + f + " not placed");
                  return false;
              }
          }
          return true;
      }
docs: Are all rings in the Vector placed?
  
  @param rings The Vector to be checked
  @return true if all rings are placed, false otherwise