def request_user_auth(code, redirect_uri)
      response = http_client(MXIT_AUTH_TOKEN_URI) do |http, path|

        request = new_post_request(path, {
          "grant_type" => "authorization_code",
          "code" => code,
          "redirect_uri" => redirect_uri
        })

        http.request(request)
      end

      @auth_token = AuthToken.new(handle_response(response))
    end
def request_user_auth(code, redirect_uri)
      response = http_client(MXIT_AUTH_TOKEN_URI) do |http, path|

        request = new_post_request(path, {
          "grant_type" => "authorization_code",
          "code" => code,
          "redirect_uri" => redirect_uri
        })

        http.request(request)
      end

      @auth_token = AuthToken.new(handle_response(response))
    end
NOTE: `user_code_request_uri` must be used before `request_user_auth` because it provides the
 `code` argument. `redirect_uri` must match the one used in the `user_code_request_uri` call