python client crashes because of auth_token type

When initializing a client object with the following lines:

import ceilometerclient.client as clients
client = clients.get_client('2',ceilometer_url="IP:PORT" ,os_auth_token= context.to_dict()['auth_token'])

this error is displayed when a query is performed:

File "/opt/stack/python-ceilometerclient/ceilometerclient/common/http.py", line 182, in json_request
resp, body_iter = self._http_request(url, method, **kwargs)
File "/opt/stack/python-ceilometerclient/ceilometerclient/common/http.py", line 132, in _http_request
auth_token = self.auth_token()
TypeError: 'unicode' object is not callable

Having a look at the get_client function in ceilometer/client.py, it can be seen that auth_token is changed to a lambda in the elif, but not in the if:

    if kwargs.get('os_auth_token') and kwargs.get('ceilometer_url'):
        token = kwargs.get('os_auth_token') """NOT CHANGED"""
        endpoint = kwargs.get('ceilometer_url')
    elif (kwargs.get('os_username') and
          kwargs.get('os_password') and
          kwargs.get('os_auth_url') and
          (kwargs.get('os_tenant_id') or kwargs.get('os_tenant_name'))):

        ks_kwargs = {
            'username': kwargs.get('os_username'),
            'password': kwargs.get('os_password'),
            'tenant_id': kwargs.get('os_tenant_id'),
            'tenant_name': kwargs.get('os_tenant_name'),
            'auth_url': kwargs.get('os_auth_url'),
            'region_name': kwargs.get('os_region_name'),
            'service_type': kwargs.get('os_service_type'),
            'endpoint_type': kwargs.get('os_endpoint_type'),
            'cacert': kwargs.get('os_cacert'),
            'insecure': kwargs.get('insecure'),
        }

        _ksclient = _get_ksclient(**ks_kwargs)
        token = ((lambda: kwargs.get('os_auth_token')) """CHANGED"""
                 if kwargs.get('os_auth_token')
                 else (lambda: _ksclient.auth_token))

so "token" could have different types depending on the case.