code: @Override
      public IElectronContainer removeElectronContainer(int number) {
          if (number < this.bondCount) return removeBond(number);
          number -= this.bondCount;
          if (number < this.lonePairCount) return removeLonePair(number);
          number -= this.lonePairCount;
          if (number < this.singleElectronCount)
              return removeSingleElectron(number);
          return null;
      }
docs: {@inheritDoc}