'Fails unless the given path points to an existing directory.
The path can be given as an exact path or as a glob pattern.
The pattern matching syntax is explained in `introduction`.
The default error message can be overridden with the ``msg`` argument.'

def directory_should_exist(self, path, msg=None):

    path = self._absnorm(path)
    matches = [p for p in self._glob(path) if os.path.isdir(p)]
    if (not matches):
        self._fail(msg, ("Directory    '%s'    does    not    exist." % path))
    self._link("Directory    '%s'    exists.", path)
