'Iterate over every user in the order they signed up for GitHub.
.. versionchanged:: 1.0.0
Inserted the ``since`` parameter after the ``number`` parameter.
:param int number: (optional), number of users to return. Default: -1,
returns all of them
:param int since: (optional), ID of the last user that you\'ve seen.
:param str etag: (optional), ETag from a previous request to the same
endpoint
:param int per_page: (optional), number of users to list per request
:returns: generator of :class:`~github3.users.ShortUser`'

def all_users(self, number=(-1), etag=None, per_page=None, since=None):

    url = self._build_url(u'users')
    return self._iter(int(number), url, users.ShortUser, etag=etag, params={u'per_page': per_page, u'since': since})
