'Assert that strings were not logged
Parameters
s : string or list/set/tuple of strings
Test should succeed if the string (or at least one of the listed) is not
present in the log
all : boolean (default False) if True should fail if any of s logged'

def assertNotLogged(self, *s, **kwargs):

    logged = self._log.getvalue()
    if (not kwargs.get('all', False)):
        for s_ in s:
            if (s_ not in logged):
                return
        if True:
            self.fail(('All    of    the    %r    were    found    present    in    the    log:    ===\n%s===' % (s, logged)))
    else:
        for s_ in s:
            if (s_ in logged):
                self.fail(('%r    was    found    in    the    log:    ===\n%s===' % (s_, logged)))
