code: @Override
      public Double getMultiplier(IAtomContainer container) {
          for (int i = 0; i < atomContainerCount; i++) {
              if (atomContainers[i].equals(container)) {
                  return multipliers[i];
              }
          }
          return -1.0;
      }
docs: Returns the multiplier of the given AtomContainer.
  
  @param  container  The AtomContainer for which the multiplier is given
  @return            -1, if the given molecule is not a container in this set
  @see               #setMultiplier(IAtomContainer, Double)