docs: function createRule(path, handler) {
    if ('*' !== path && 0 != path.indexOf(watch.__base)) {
      path = watch.__base + (path == '/' ? '' : path)
    }
    let rule = pathToRegExp(path)
    if (handler instanceof String) {
      let target = handler
      handler = function() {
        watch({
          url: target
        })
      }
    }
    rule.handler = handler
  
    return rule
  }