Import the definition of __general_m3u8_extractor()__ for the function call on line 64...
flake8 testing of https://github.com/soimort/you-get on Python 3.6.3
$ __flake8 . --count --select=E901,E999,F821,F822,F823 --show-source --statistics__
```
./src/you_get/extractors/longzhu.py:63:20: F821 undefined name 'general_m3u8_extractor'
urls = general_m3u8_extractor(real_url)
^
1 F821 undefined name 'general_m3u8_extractor'
```