AuthenticatesUsers.php

<?php
  trait AuthenticatesUsers {
    public function getLogin() {
      if (view()->exists('auth.authenticate')) {
        return view('auth.authenticate');
      }

      return view('auth.login');
    }
  }

Foo.php

<?php
  class Foo {
    use AuthenticatesUsers;
    
    public function getLogin() {
      // Do my stuff
      parent::getLogin();
    }
  }