code: public static JavaClass lookupSystemClass(@Nonnull String className) throws ClassNotFoundException {
          // TODO: eventually we should move to our own thread-safe repository
          // implementation
          requireNonNull (className, "className is null");
          if (originalRepository == null) {
              throw new IllegalStateException("originalRepository is null");
          }
  
          JavaClass clazz = originalRepository.findClass(className);
          if(clazz != null){
              return clazz;
          }
          // XXX workaround for system classes missing on Java 9
          // Not sure if we BCEL update, but this seem to work in simple cases
          return AnalysisContext.currentAnalysisContext().lookupClass(className);
      }
docs: This is equivalent to Repository.lookupClass() or this.lookupClass(),
  except it uses the original Repository instead of the current one.
  
  This can be important because URLClassPathRepository objects are closed
  after an analysis, so JavaClass objects obtained from them are no good on
  subsequent runs.
  
  @param className
  the name of the class
  @return the JavaClass representing the class
  @throws ClassNotFoundException