Limit test for correct calls to python versions >= 3.8

Author: pkess

test/test_player.py

@@ -62,8 +62,10 @@ def test_play_virtual(self):
             data=[0x5, 0xC, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0],
         )
         self.assertEqual(self.MockSleep.call_count, 2)
-        self.assertTrue(msg1.equals(self.mock_virtual_bus.send.mock_calls[0].args[0]))
-        self.assertTrue(msg2.equals(self.mock_virtual_bus.send.mock_calls[1].args[0]))
+        if sys.version_info.major > 3 or sys.version_info.minor >= 8:
+            # The args argument was introduced with python 3.8
+            self.assertTrue(msg1.equals(self.mock_virtual_bus.send.mock_calls[0].args[0]))
+            self.assertTrue(msg2.equals(self.mock_virtual_bus.send.mock_calls[1].args[0]))
         self.assertSuccessfulCleanup()
 
     def test_play_virtual_verbose(self):