Map<String, ClassNode> refactored = new HashMap<>();
for (ClassNode cn : getContainer().getNodes().values()) {
String oldName = cn.name;
ClassReader cr = new ClassReader(getClassNodeBytes(cn));
ClassWriter cw = new ClassWriter(cr, 0);
RemappingClassAdapter rca = new RemappingClassAdapter(cw, mapper);
cr.accept(rca, ClassReader.EXPAND_FRAMES);
cr = new ClassReader(cw.toByteArray());
cn = new ClassNode();
cr.accept(cn, 0);
refactored.put(oldName, cn);