Created a failing test.

src/icalendar/tests/test_fixed_issues.py

@@ -5,6 +5,7 @@ import datetime
 import os
 import pytz
 
+
 class TestIssues(unittest.TestCase):
 
 
@@ -130,3 +131,8 @@ END:VEVENT"""
             "BEGIN:VEVENT\r\nATTACH;ENCODING=BASE64;FMTTYPE=text/plain;"
             "VALUE=BINARY:dGV4dA==\r\nEND:VEVENT\r\n"
         )
+
+
+    def test_wrong_values(self):
+        ical_content = "BEGIN:VEVENT\r\nSUMMARY;LANGUAGE=ru:te\r\nEND:VEVENT"
+        icalendar.Event.from_ical(ical_content).to_ical()

src/icalendar/tests/test_timezoned.py

@@ -7,6 +7,7 @@ import os
 
 from . import unittest
 
+
 class TestTimezoned(unittest.TestCase):
 
     def test_create_from_ical(self):

src/icalendar/tests/test_unit_tools.py

@@ -1,6 +1,7 @@
 from . import unittest
 from icalendar.tools import UIDGenerator
 
+
 class TestTools(unittest.TestCase):
 
     def test_tools_UIDGenerator(self):