mv = cw.visitMethod(Opcodes.ACC_PUBLIC|Opcodes.ACC_STATIC, "make_tuple", sb.toString(), null, null);
mv.visitCode();
mv.visitTypeInsn(Opcodes.NEW, this_class_name);
mv.visitInsn(Opcodes.DUP);
mv.visitMethodInsn(Opcodes.INVOKESPECIAL, this_class_name, "<init>",
"()V");
for (int i = 0; i < arity; i++) {
mv.visitInsn(Opcodes.DUP);
mv.visitVarInsn(Opcodes.ALOAD, i);