How to Unset Request Data in CakePHP 3.4

I’ve tried to search this but I found no luck.

It says that $request->data will be deprecated in 4.0 and suggesting to use $request->getData() instead.

How do I unset request data when we don’t have the option to unset it?

This is useful when logging in or registering with password. When they failed the validation, they have to retype the password.

Request is immutable after 3.4.
You should not change any value of the request datas.
But maybe you can try $this->request = $this->request->withData('password', null);