TypeError: argument of type 'NoneType' is not iterable

Traceback (most recent call last):
  File "./mongoaudit", line 31, in <module>
    main()
  File "/home/adansdpc/Stampery/Desarrollo/mongoaudit/src/main.py", line 62, in main
    App().main()
  File "/home/adansdpc/Stampery/Desarrollo/mongoaudit/src/main.py", line 22, in __init__
    self.main()
  File "/home/adansdpc/Stampery/Desarrollo/mongoaudit/src/main.py", line 57, in main
    self.loop.run()
  File "/home/adansdpc/anaconda2/lib/python2.7/site-packages/urwid/main_loop.py", line 278, in run
    self._run()
  File "/home/adansdpc/anaconda2/lib/python2.7/site-packages/urwid/main_loop.py", line 376, in _run
    self.event_loop.run()
  File "/home/adansdpc/anaconda2/lib/python2.7/site-packages/urwid/main_loop.py", line 682, in run
    self._loop()
  File "/home/adansdpc/anaconda2/lib/python2.7/site-packages/urwid/main_loop.py", line 719, in _loop
    self._watch_files[fd]()
  File "/home/adansdpc/anaconda2/lib/python2.7/site-packages/urwid/raw_display.py", line 393, in <lambda>
    event_loop, callback, self.get_available_raw_input())
  File "/home/adansdpc/anaconda2/lib/python2.7/site-packages/urwid/raw_display.py", line 493, in parse_input
    callback(processed, processed_codes)
  File "/home/adansdpc/anaconda2/lib/python2.7/site-packages/urwid/main_loop.py", line 403, in _update
    self.process_input(keys)
  File "/home/adansdpc/anaconda2/lib/python2.7/site-packages/urwid/main_loop.py", line 503, in process_input
    k = self._topmost_widget.keypress(self.screen_size, k)
  File "/home/adansdpc/anaconda2/lib/python2.7/site-packages/urwid/container.py", line 592, in keypress
    *self.calculate_padding_filler(size, True)), key)
  File "/home/adansdpc/anaconda2/lib/python2.7/site-packages/urwid/container.py", line 1587, in keypress
    key = self.focus.keypress(tsize, key)
  File "/home/adansdpc/Stampery/Desarrollo/mongoaudit/src/widgets.py", line 213, in keypress
    return self.__super.keypress(size, key)
  File "/home/adansdpc/anaconda2/lib/python2.7/site-packages/urwid/container.py", line 1587, in keypress
    key = self.focus.keypress(tsize, key)
  File "/home/adansdpc/anaconda2/lib/python2.7/site-packages/urwid/decoration.py", line 621, in keypress
    return self._original_widget.keypress(maxvals, key)
  File "/home/adansdpc/anaconda2/lib/python2.7/site-packages/urwid/container.py", line 1587, in keypress
    key = self.focus.keypress(tsize, key)
  File "/home/adansdpc/anaconda2/lib/python2.7/site-packages/urwid/container.py", line 1587, in keypress
    key = self.focus.keypress(tsize, key)
  File "/home/adansdpc/Stampery/Desarrollo/mongoaudit/src/widgets.py", line 147, in keypress
    self.next_callback()
  File "/home/adansdpc/Stampery/Desarrollo/mongoaudit/src/widgets.py", line 183, in next
    self.callbacks['next'](form=self, **(self.get_field_values()))
  File "/home/adansdpc/Stampery/Desarrollo/mongoaudit/src/cards.py", line 90, in <lambda>
    uri, form, lambda cred: self.run_test(cred, title, tests))
  File "/home/adansdpc/Stampery/Desarrollo/mongoaudit/src/tools.py", line 41, in validate_uri
    callback(parsed)
  File "/home/adansdpc/Stampery/Desarrollo/mongoaudit/src/cards.py", line 90, in <lambda>
    uri, form, lambda cred: self.run_test(cred, title, tests))
  File "/home/adansdpc/Stampery/Desarrollo/mongoaudit/src/cards.py", line 110, in run_test
    test_runner.run(self.app)
  File "/home/adansdpc/Stampery/Desarrollo/mongoaudit/src/widgets.py", line 264, in run
    self.tester.run(self.each, self.end)
  File "/home/adansdpc/Stampery/Desarrollo/mongoaudit/src/testers/testers.py", line 38, in run
    res = test.run()
  File "/home/adansdpc/Stampery/Desarrollo/mongoaudit/src/testers/testers.py", line 143, in run
    result = TEST_FUNCTIONS[self.name](self)
  File "/home/adansdpc/Stampery/Desarrollo/mongoaudit/src/testers/testers.py", line 226, in <lambda>
    "4": lambda test: "version" not in test.tester.info,
TypeError: argument of type 'NoneType' is not iterable
stampery / mongoaudit

TypeError: argument of type 'NoneType' is not iterable #18
