How to leave only grid and helper classes in bootstrap 4?

Question

Layout

Which of these should be left so that bootstrap would have only a grid and auxiliary classes like .float-right .d-flex .text-center, etc. And if I remove some line @import, then gulp gives an error.

/*!
 * Bootstrap v4.0.0-beta (https://getbootstrap.com)
 * Copyright 2011-2017 The Bootstrap Authors
 * Copyright 2011-2017 Twitter, Inc.
 * Licensed under MIT (https://github.com/twbs/bootstrap/blob/master/LICENSE)
 */

@import "functions";
@import "variables";
@import "mixins";
@import "print";
@import "reboot";
@import "type";
@import "images";
@import "code";
@import "grid";
@import "tables";
@import "forms";
@import "buttons";
@import "transitions";
@import "dropdown";
@import "button-group";
@import "input-group";
@import "custom-forms";
@import "nav";
@import "navbar";
@import "card";
@import "breadcrumb";
@import "pagination";
@import "badge";
@import "jumbotron";
@import "alert";
@import "progress";
@import "media";
@import "list-group";
@import "close";
@import "modal";
@import "tooltip";
@import "popover";
@import "carousel";
@import "utilities";

Answer 1

Basically like this:

@import "functions";
@import "variables";
@import "mixins";
@import "grid";
@import "utilities";

If Gulp gives you some kind of error, then you need to look at what the error is.

Answer 2

Most likely you are removing something from the most basic files