Tweak expectations to have diverse results

code-samples.json

@@ -5,13 +5,19 @@
         "stderr": null,
         "exitcode": 0
     },
-    "actors-sequential2.pony": {
+    "traits-and-interfaces-private-methods.pony": {
         "runnable": true,
         "stdout": null,
-        "stderr": "This is printed first\nThis is printed last\n",
+        "stderr": "interfaces can't have private methods, only traits can\n",
         "exitcode": 1
     },
     "actors-behaviors.pony": {
         "runnable": false
+    },
+    "appendices-examples-access-command-line-arguments.pony": {
+        "runnable": true,
+        "stdout": "This is printed first\nThis is printed last\n",
+        "stderr": null,
+        "exitcode": 0
     }
 }