code: @Override
      public List<ISingleElectron> getConnectedSingleElectronsList(IAtom atom) {
          List<ISingleElectron> ses = new ArrayList<>(2);
          for (int i = 0; i < singleElectronCount; i++) {
              if (singleElectrons[i].contains(atom))
                  ses.add(singleElectrons[i]);
          }
          if (ses.isEmpty() && !contains(atom))
              throw new NoSuchAtomException("Atom does not belong to the container!");
          return ses;
      }
docs: {@inheritDoc}