Note that using % in a string will _always_ perform the sting substitutions, because the strings are constructed before the function is called. So log.debug('%s' % expensiveoperation()) will take about the same CPU time whether or not the logging level is DEBUG or INFO. if you use , no substitutions are performed unless the string is actually logged
Honestly, this is mainly just a demo/proof of concept that we
can handle dependencies and ordering issues with stream features.
DON'T use XEP-0078 if you are able to use the normal SASL method,
which should be the case unless you are dealing with a very old
XMPP server implementation.