Fix flakiness.

The opened-ports call should always be first, but after that it depends on the order of items returned from set operations, and we don't care which order they happen in, so compare the sorted items.

test/test_model.py

@@ -3411,10 +3411,13 @@ def test_set_ports(self):
         fake_script(self, 'close-port', 'exit 0')
         fake_script(self, 'opened-ports', 'exit 0')
         self.unit.set_ports(8000, 8025)
-        self.assertEqual(fake_script_calls(self, clear=True), [
-            ['opened-ports', ''],
-            ['open-port', '8025/tcp'],
+        calls = fake_script_calls(self, clear=True)
+        self.assertEqual(calls.pop(0), ['opened-ports', ''])
+        # We make no guarantee on the order the ports are opened.
+        calls.sort()
+        self.assertEqual(calls, [
             ['open-port', '8000/tcp'],
+            ['open-port', '8025/tcp'],
         ])
         fake_script(self, 'opened-ports', 'echo 8025/tcp')
         self.unit.set_ports(ops.Port('udp', 8022))