def valid_param?(api:, param:)
      rest_api = get(api)
      return true if rest_api.nil?
      rest_api.valid_param?(param)
    end
def valid_param?(api:, param:)
      rest_api = get(api)
      return true if rest_api.nil?
      rest_api.valid_param?(param)
    end
Given an API descriptor name and a single request parameter, returns
 `true` if the parameter is valid for the given API. This method always
 returns `true` if the API is unknown.

 api   - the api descriptor name as a String
 param - the request parameter name as a String

 Returns `true` if the param is valid for the API.