def select_parts(api:, from:)
      rest_api = get(api)
      return from if rest_api.nil?
      rest_api.select_parts(from: from)
    end
def select_parts(api:, from:)
      rest_api = get(api)
      return from if rest_api.nil?
      rest_api.select_parts(from: from)
    end
Given an API descriptor name and a set of request path parts, select those
 parts that are accepted by the API endpoint.

 api  - the api descriptor name as a String
 from - the Hash containing the path parts

 Returns a new Hash containing the valid path parts for the api