code: private static IChemObjectBuilder findBuilder() {
          if (BUILDER != null)
              return BUILDER;
          for (String name : new String[]{
                  "org.openscience.cdk.silent.SilentChemObjectBuilder",
                  "org.openscience.cdk.DefaultChemObjectBuilder"
          }) {
              try {
                  Class<?> cls    = Class.forName(name);
                  Method   method = cls.getMethod("getInstance");
                  return BUILDER = (IChemObjectBuilder) method.invoke(cls);
              } catch (Exception ex) {
                  // ignored
              }
          }
          return null;
      }
docs: with the query