@Override
    protected boolean execute(
            CtClass inputClass,
            String inputClassName,
            CtConstructor initializer)
            throws CannotCompileException, NotFoundException {

        String target = getTarget();

        target = getReplaceStatement(inputClassName, initializer, true, target);
        if (isAsBefore()) {
            initializer.insertBefore(target);
            Logger.warning(getPrettyName() + " insert after execution by: " + target
                    + " at " + inputClassName + ".java" + ":" + initializer.getName());
        }
        if (isAsAfter()) {
            initializer.insertAfter(target);
            Logger.warning(getPrettyName() + " insert after execution by: " + target
                    + " at " + inputClassName + ".java" + ":" + initializer.getName());
        }
        return true;
    }
Transform that inserts custom code at the pointcut where initializer executes.
plugin/src/main/groovy/com/didichuxing/tools/droidassist/transform/insert/InitializerExecutionInsertTransformer.java