How to use the tui-code-snippet/domUtil/removeClass function in tui-code-snippet

makeEnable() {
    this.nativeEl.disabled = false;
    removeClass(this.el, cls.DISABLED);
  }

dehighlight() {
    removeClass(this.el, cls.HIGHLIGHT);
    this.el.blur();
  }

changeDisabled(disabled) {
    if (this.disabled !== disabled) {
      this.disabled = this.nativeEl.disabled = disabled;
      if (disabled) {
        addClass(this.el, DISABLED_CLASS_NAME);
      } else {
        removeClass(this.el, DISABLED_CLASS_NAME);
      }
    }
  }

enable() {
    this.disabled = this.nativeEl.disabled = false;
    removeClass(this.labelEl, cls.DISABLED);
    this.items.forEach(item => item.enableItemGroup());
  }

changeSelected(selected) {
    this.selected = this.nativeEl.selected = selected;
    if (selected) {
      addClass(this.el, SELECTED_CLASS_NAME);
    } else {
      removeClass(this.el, SELECTED_CLASS_NAME);
    }
  }

enable() {
    this.nativeEl.disabled = false;
    removeClass(this.el, cls.DISABLED);
  }

changeOpened(opened) {
    if (opened) {
      removeClass(this.el, HIDDEN_CLASS_NAME);
      if (this.selectedOption) {
        this.highlight();
      }
    } else {
      addClass(this.el, HIDDEN_CLASS_NAME);
      this.dehighlight();
    }
  }

changeHighlight(highlight) {
    if (highlight) {
      addClass(this.el, HIGHLIGHT_CLASS_NAME);
    } else {
      removeClass(this.el, HIGHLIGHT_CLASS_NAME);
    }
  }

close() {
    removeClass(this.el, cls.OPEN);
  }