docs: function normalize(route) {
    if (is.not.array(route.path) && is.not.string(route.path)) {
      throw new Error(ERR_NORMALIZE_ROUTE);
    }
  
    if (is.array(route.method)) {
      /* If method is an array */
      route.method.forEach((method, i) => {
        route.method[i] = method.toLowerCase();
      });
    }
  
    /* If method is a string */
    if (is.string(route.method)) {
      route.method = route.method.toLowerCase();
    }
  
    return route;
  }