code: private void writeRemappedClass(URL classUrl, JarOutputStream jarStream, String targetPackage) throws IOException {
          InputStream inputStream = classUrl.openStream();
          String sourceInternalName = getClassInternalName(classUrl);
          String targetInternalName = getTargetInternalName(sourceInternalName, targetPackage);
          SimpleRemapper remapper = new SimpleRemapper(sourceInternalName, targetInternalName);
  
          ClassReader reader = new ClassReader(inputStream);
          ClassWriter writer = new ClassWriter(reader, ClassWriter.COMPUTE_FRAMES);
          ClassRemapper remappingVisitor = new ClassRemapper(writer, remapper);
          ClassVisitor versionVisitor = new AddVersionFieldClassAdapter(remappingVisitor, VERSION_FIELD_NAME, getCurrentVersion());
          reader.accept(versionVisitor, ClassReader.EXPAND_FRAMES);
  
          JarEntry jarEntry = new JarEntry(targetInternalName + ".class");
          jarStream.putNextEntry(jarEntry);
          jarStream.write(writer.toByteArray());
      }
docs: Transform the proxy template class that's in this package into a class
  that's in a package on the framework boot delegation package list.
  
  @return the byte array containing the updated class
  
  @throws IOException if an IO exception raised while processing the class