+ :param str channel: Channel to use when getting the charm from the
+ charm store, e.g. 'development'
+ :param bool force_series: Upgrade even if series of deployed service
+ is not supported by the new charm
+ :param bool force_units: Upgrade all units immediately, even if in
+ error state
+ :param str path: Uprade to a charm located at path
+ :param dict resources: Dictionary of resource name/filepath pairs
+ :param int revision: Explicit upgrade revision
+ :param str switch: Crossgrade charm url
+