[Twisted-Python] reverse web proxy & threads

[Artem Bokhan]

Hello!

I'm playing with reverse proxy from examples
(Twisted-8.2.0/doc/web/examples/proxy.py). May somebody explain what
part of code uses threads there?

pstree -p | grep python

-python(12786)-+-{python}(12795)
                |-{python}(13050)
                |-{python}(15547)
                `-{python}(20767)