How do interfaces make the trait's methods work?

Question

PHP

In Laravel, you need to make imlements of the MustVerifyEmail interface and verification by email starts working. Can't figure out how it's done? Interface - regulates which methods need to be created or overridden in the class. But these methods are already in the class, regardless of the implementation of the interface. How does an interface change functionality?

Answer 1

somewhere in the code there is a stupid check

if ($obj instanceof MustVerifyEmail) { 
    ... 
}