CodeIgniter 4: built-in validation methods

i am following a video guide, in which he demonstrated some validations like: required, is_unique, min_length[n] etc. 
i want to have a list of these built in validations and if possible, with example. please help with a link the list of built-in validation methods.
regards

See https://codeigniter4.github.io/userguide...able-rules

ci-phpunit-test | CodeIgniter Testing Guide | CodeIgniter 3 to 4 Upgrade Helper

See https://codeigniter4.github.io/userguide...able-rules

thanks a bunch @kenjis for quick help.