30. A method according to claim 29 , wherein the code is configured such that the second HTTP request is a last HTTP GET request carried out by the web browser when processing the HTTP response.
29. An apparatus-implemented method carried out by a system comprising a processor and a memory, the method comprising: receiving, by a client proxy, of a first HTTP GET request generated by a web browser of a client apparatus for a first URL; recording, by the client proxy, of time of receipt of the first HTTP GET request; editing, by the client proxy, of Javascript to provide code configured to cause the web browser of the client apparatus to generate a second HTTP request; sending, by the client proxy, to the web browser of the client apparatus of an HTTP response comprising the code; generating by the web browser of the client apparatus of the second HTTP request in response to receipt of the HTTP response comprising the code; receiving, by the client proxy, of the second HTTP request; recording, by the client proxy, of time of receipt of the second HTTP request; and computing a response time in accordance with a difference between the time of receipt of the first HTTP GET request as recorded by the client proxy and the time of receipt of the second HTTP request as recorded by the client proxy.