Laravel getting error when running tinker

I am using laravel 5.2 and I am getting error when I am trying to use php artisan tinker. I am using php 7.1.

When I am running:

php artisan tinker

I am getting this error:

 [Symfony\Component\Debug\Exception\FatalThrowableError]
  Call to undefined function Laravel\Tinker\tap()

I upgraded my laravel from 5.2 to 5.5 but most of my previous function don't work. So I revert back to 5.2 but I am getting this error.

via Chebli Mohamed