code: private void callDefaultRestrictions() throws CDKException, IOException {
  
          List<IRule> rules1 = new ArrayList<IRule>();
          IsotopeFactory ifac = Isotopes.getInstance();
  
          // restriction for occurrence elements
          MolecularFormulaRange mfRange1 = new MolecularFormulaRange();
          mfRange1.addIsotope(ifac.getMajorIsotope("C"), 0, 15);
          mfRange1.addIsotope(ifac.getMajorIsotope("H"), 0, 15);
          mfRange1.addIsotope(ifac.getMajorIsotope("N"), 0, 15);
          mfRange1.addIsotope(ifac.getMajorIsotope("O"), 0, 15);
  
          IRule rule = new ElementRule();
          Object[] params = new Object[1];
          params[0] = mfRange1;
          rule.setParameters(params);
  
          rules1.add(rule);
  
          // occurrence for charge
          rule = new ChargeRule(); // default 0.0 neutral
          rules1.add(rule);
          charge = (Double) ((Object[]) rule.getParameters())[0];
  
          // occurrence for tolerance
          rule = new ToleranceRangeRule(); // default 0.05
          rules1.add(rule);
          this.tolerance = (Double) ((Object[]) rule.getParameters())[1];
  
          this.matrix_Base = getMatrix(mfRange1.getIsotopeCount());
  
          this.mfRange = mfRange1;
          this.rules = rules1;
  
      }
docs: Create the default restrictions. They are:<p>
  
  The major isotopes = C, H, O and N<p>
  Charge = 0.0, indicating neutral compound<p>
  Tolerance = 0.05 amu<p>
  @throws ClassNotFoundException
  @throws IOException
  @throws CDKException
  @throws IOException