@classmethod
def set_channel_layout(cls, client, channel_id, layout, layout_id='1'):
    """returns the json layout set.

        layout must be a json string
        """
    path = '/admin/channel%s/layouts/%s' % (channel_id, layout_id)
    extra_headers = {'Content-Type': 'application/json; charset=UTF-8'}
    r = client.post(path=path, data=layout, extra_headers=extra_headers)
    return r.text
