delete(cache.iamGroupsMap, group)
		cache.iamGroupPolicyMap.Delete(group)

		cache.updatedAt = time.Now()
		return nil
	}

	gi := cache.iamGroupsMap[group]

	// Updating the group memberships cache happens in two steps:
	//
	// 1. Remove the group from each user's list of memberships.
	// 2. Add the group to each member's list of memberships.
	//

		return
	}

	user, exists := globalIAMSys.GetUser(ctx, accessKey)
	if exists && (user.Credentials.IsTemp() || user.Credentials.IsServiceAccount()) {
		// Updating STS credential is not allowed, and this API does not
		// support updating service accounts.
		writeErrorResponseJSON(ctx, w, errorCodes.ToAPIErr(ErrAddUserInvalidArgument), r.URL)
		return
	}

		queued:    time.Now(),
	})
}

func (er erasureObjects) PutObjectMetadata(ctx context.Context, bucket, object string, opts ObjectOptions) (ObjectInfo, error) {
	if !opts.NoLock {
		// Lock the object before updating metadata.
		lk := er.NewNSLock(bucket, object)
		lkctx, err := lk.GetLock(ctx, globalOperationTimeout)
		if err != nil {
			return ObjectInfo{}, err
		}
		ctx = lkctx.Context()
		defer lk.Unlock(lkctx)