code: @Override
      public void addSingleElectron(ISingleElectron singleElectron) {
          if (singleElectronCount >= singleElectrons.length) growSingleElectronArray();
          singleElectrons[singleElectronCount] = singleElectron;
          ++singleElectronCount;
          notifyChanged();
      }
docs: Adds a single electron to this AtomContainer.
  
  @param  singleElectron  The SingleElectron to added to this container