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

        String insnClassName = newExpr.getClassName();
        String insnSignature = newExpr.getSignature();

        if (!isMatchConstructorSource(insnClassName, insnSignature)) {
            return false;
        }

        String target = getTarget();

        if (!target.startsWith("$_=") || !target.startsWith("$_ =")) {
            if (target.startsWith("{")) {
                target = "{" + "$_=" + target.substring(1);
            } else {
                target = "$_=" + target;
            }
        }

        String replacement = replaceInstrument(inputClassName, newExpr, target);

        Logger.warning(getPrettyName() + "by: " + replacement
                + " at " + inputClassName + ".java" + ":" + newExpr.getLineNumber());
        return true;
    }
Transform that replaces constructor-call with new code.
plugin/src/main/groovy/com/didichuxing/tools/droidassist/transform/replace/ConstructorCallReplaceTransformer.java