update README

Author: mtkp

README.md

@@ -26,7 +26,21 @@ Whenever you make an http request, add one or more of the hystrix-clj options to
                                    :hystrix/breaker-sleep-window-ms 5000
                                    :hystrix/bad-request-pred        client-error?})
 ```
-Any values not supplied will be set to their default values as above. Requests with no Hystrix-related keys won't use Hystrix.
+
+Requests without any `:hystrix/...` keys won't use Hystrix. Any values not supplied will be set to their default values as above. Custom default values can also be specified when registering with `add-hook`:
+
+```clj
+(clj-http-hystrix.core/add-hook {:hystrix/timeout-ms 2500
+                                 :hystrix/queue-size 12})
+
+;; now each request will fallback to these if not supplied
+(http/get "http://www.google.com" {:hystrix/command-key :google})
+;;=> {:hystrix/command-key :google
+;;    :hystrix/timeout-ms 2500
+;;    :hystrix/queue-size 12
+;;    ... (rest are clj-http-hystrix defaults)
+;;    }
+```
 
 ## Bad requests
 

src/clj_http_hystrix/core.clj

@@ -111,14 +111,15 @@
         (let [req (merge defaults req)
               bad-request-pred (:hystrix/bad-request-pred req)
               fallback (:hystrix/fallback-fn req)
-              wrap-bad-request (fn [resp] (if (bad-request-pred req resp)
-                                            (throw
-                                              (HystrixBadRequestException.
-                                                "Ignored bad request"
-                                                (wrap {:object resp
-                                                       :message "Bad request pred"
-                                                       :stack-trace (stack-trace)})))
-                                            resp))
+              wrap-bad-request (fn [resp]
+                                 (if (bad-request-pred req resp)
+                                   (throw
+                                     (HystrixBadRequestException.
+                                       "Ignored bad request"
+                                       (wrap {:object resp
+                                              :message "Bad request pred"
+                                              :stack-trace (stack-trace)})))
+                                   resp))
               wrap-exception-response (fn [resp]
                                         ((http/wrap-exceptions (constantly resp))
                                          (assoc req :throw-exceptions true)))