Extended ISO-8601 datetime values reported as invalid.

[fake-name]

I wound up here from what I think is an answer posted by the author of this library here.

I'm trying to parse extended ISO-8601 date/time stamps:

• 2008-09-03T20:56:35.450686Z
• 2019-05-27T04:31:03.501407232Z

The linked question above seems to indicate that these would work, but they now fail:

Traceback (most recent call last):
  File "magplot.py", line 27, in <module>
    r2 = iso8601utils.parsers.datetime('2008-09-03T20:56:35.450686Z')
  File "C:\Python37\lib\site-packages\iso8601utils\parsers.py", line 52, in datetime
    raise e
  File "C:\Python37\lib\site-packages\iso8601utils\parsers.py", line 50, in datetime
    return datetime_helper(datetime)
  File "C:\Python37\lib\site-packages\iso8601utils\parsers.py", line 170, in datetime_helper
    raise ValueError('Invalid ISO 8601 datetime.')
ValueError: Invalid ISO 8601 datetime.

Traceback (most recent call last):
  File "magplot.py", line 28, in <module>
    ret = iso8601utils.parsers.datetime("2019-05-27T04:31:03.501407232Z")
  File "C:\Python37\lib\site-packages\iso8601utils\parsers.py", line 52, in datetime
    raise e
  File "C:\Python37\lib\site-packages\iso8601utils\parsers.py", line 50, in datetime
    return datetime_helper(datetime)
  File "C:\Python37\lib\site-packages\iso8601utils\parsers.py", line 170, in datetime_helper
    raise ValueError('Invalid ISO 8601 datetime.')
ValueError: Invalid ISO 8601 datetime.

I can't find any tests of the extended datetime values in the tests. Are these no longer supported?