setTheme (theme, optionsOverride = false) {
    if (this.barDom) {
      let classList = Utils.classList(this.barDom).split(' ')

      classList.forEach(c => {
        if (c.substring(0, 12) === 'noty_theme__') {
          Utils.removeClass(this.barDom, c)
        }
      })

      Utils.addClass(this.barDom, `noty_theme__${theme}`)
    }

    if (optionsOverride) this.options.theme = theme

    return this
  }
@param {string} theme
@param {boolean} optionsOverride
@return {Noty}