NT_HIDDEN)\n    })\n  }\n\n  _removeBackdrop() {\n    if (this._backdrop) {\n      $(this._backdrop).remove()\n      this._backdrop = null\n    }\n  }\n\n  _showBackdrop(callback) {\n    const animate = $(this._element).hasClass(CLASS_NAME_FADE) ?\n      CLASS_NAME_FADE : ''\n\n    if (this._isShown && this._config.backdrop) {\n      this._backdrop = document.createElement('div')\n      this._backdrop.className = CLASS_NAME_BACKDROP\n\n      if (animate) {\n        this._backdrop.classList.add(animate)\n...

this check in v6\n    if (!tip) {\n      return null\n    }\n\n    tip.classList.remove(CLASS_NAME_FADE, CLASS_NAME_SHOW)\n    // TODO: v6 the following can be achieved with CSS only\n    tip.classList.add(`bs-${this.constructor.NAME}-auto`)\n\n    const tipId = getUID(this.constructor.NAME).toString()\n\n    tip.setAttribute('id', tipId)\n\n    if (this._isAnimated()) {\n      tip.classList.add(CLASS_NAME_FADE)\n    }\n\n    return tip\n  }\n\n  setContent(content) {\n    this._newContent = content\n...