Prerequisites to a class action.
Class actions maintainable.
An order under this subdivision may be conditional, and may be altered or amended before the decision on the merits. Orders in conduct of actions. The orders may be combined with an order under Rule 16, and may be altered or amended as may be desirable from time to time. Dismissal or compromise. A class action shall not be dismissed or compromised without the approval of the court, and notice of the proposed dismissal or compromise shall be given to all members of the class in such manner as the court directs.