code: private void growSingleElectronArray() {
          growArraySize = (singleElectrons.length < growArraySize) ? growArraySize : singleElectrons.length;
          ISingleElectron[] newSingleElectrons = new ISingleElectron[singleElectrons.length + growArraySize];
          System.arraycopy(singleElectrons, 0, newSingleElectrons, 0, singleElectrons.length);
          singleElectrons = newSingleElectrons;
      }
docs: Grows the single electron array by a given size.
  
  @see    #growArraySize