code: @Override
      public boolean matches(IBond bond) {
          return bond.isAromatic() || bond.getOrder() == IBond.Order.SINGLE;
      }
docs: /*
  (non-Javadoc)
  @see
  org.openscience.cdk.isomorphism.matchers.smarts.SMARTSBond#matches(org
  .openscience.cdk.interfaces.IBond)