@Override
 public void visitInsn(final int opcode) {
   if (opcode == Opcodes.DUP) {
     machine.gotDup();
     if (machine.skipInstruction()) return;
   }
   super.visitInsn(opcode);
 }
 public void visitInsn(final int opcode) {
   if (opcode == RETURN) {
     for (Iterator i4 = m_mixinFields.values().iterator(); i4.hasNext(); ) {
       MixinFieldInfo fieldInfo = (MixinFieldInfo) i4.next();
       if (!fieldInfo.isStatic) {
         initializeMemberMixinField(mv, fieldInfo);
       }
     }
   }
   super.visitInsn(opcode);
 }