prepareParams = (userParams, mixinParams) => {
  const templateParams = getTemplateParams(userParams)
  const params = Object.assign({}, defaultParams, mixinParams, templateParams, userParams) // precedence is described in #2131
  params.showClass = Object.assign({}, defaultParams.showClass, params.showClass)
  params.hideClass = Object.assign({}, defaultParams.hideClass, params.hideClass)
  if (params.animation === false) {
    params.showClass = {
      backdrop: 'swal2-noanimation',
    }
    params.hideClass = {}
  }
  return params
}
@param {SweetAlertOptions} userParams
@param {SweetAlertOptions} mixinParams
@returns {SweetAlertOptions}