def request_parameters
      Hash[(Tumblr::Client::POST_OPTIONS | [:id, :type]).map {|key|
        [key.to_s, send(key)] if respond_to?(key) && send(key)
      }.compact]
    end
def request_parameters
      Hash[(Tumblr::Client::POST_OPTIONS | [:id, :type]).map {|key|
        [key.to_s, send(key)] if respond_to?(key) && send(key)
      }.compact]
    end
Transform this Post into a hash ready to be serialized and posted to the API.
 This looks for the fields of Tumblr::Client::POST_OPTIONS as methods on the object.