make sure that the edge case of an empty quoted string is considered

src/icalendar/tests/events/issue_355_url_escaping_empty_param.ics

@@ -0,0 +1,3 @@
+BEGIN:VEVENT
+ORGANIZER;CN="":that
+END:VEVENT

src/icalendar/tests/test_issue_355_url_escaping.py

@@ -17,3 +17,7 @@ def test_other_facebook_link_is_correctly_parsed(events):
     """
     expected_result = 'https://www.facebook.com/events/756119502186737/?acontext=%7B%22source%22%3A5%2C%22action_history%22%3A[%7B%22surface%22%3A%22page%22%2C%22mechanism%22%3A%22main_list%22%2C%22extra_data%22%3A%22%5C%22[]%5C%22%22%7D]%2C%22has_source%22%3Atrue%7D'
     assert events.issue_355_url_escaping_2["DESCRIPTION"] == expected_result
+
+def test_empty_quotes(events):
+    """Make sure that empty quoted parameter values are supported."""
+    assert events.issue_355_url_escaping_empty_param['ORGANIZER'].params['CN'] == ""