成员的完整列表，这些成员属于 NIMRevokeMessageNotification,包括所有继承而来的类成员

	attach	NIMRevokeMessageNotification
	callbackExt	NIMRevokeMessageNotification
	fromUserId	NIMRevokeMessageNotification
	message	NIMRevokeMessageNotification
	messageFromUserId	NIMRevokeMessageNotification
	notificationType	NIMRevokeMessageNotification
	offline	NIMRevokeMessageNotification
	postscript	NIMRevokeMessageNotification
	roaming	NIMRevokeMessageNotification
	session	NIMRevokeMessageNotification
	timestamp	NIMRevokeMessageNotification