diff --git a/lib/purge.js b/lib/purge.js
index <HASH>..<HASH> 100644
--- a/lib/purge.js
+++ b/lib/purge.js
@@ -132,6 +132,21 @@ function AkamaiPurgeRequestBody(urls, options) {
 }
 
 function AkamaiPurgeResponse(rawBody, callback) {
+  var body, keys;
+
+  Object.defineProperties(this, {
+    '_body': {
+      enumerable: false,
+      get: function() { return body; },
+      set: function(value) { body = value; }
+    },
+    '_keys': {
+      enumerable: false,
+      get: function() { return keys; },
+      set: function(value) { keys = value; }
+    }
+  });
+
   this.setBody(rawBody).process(callback);
 }
made purge body and keys properties innumerable