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.
	//
	// This ensures that regardless of members being added or
	// removed, the cache stays current.

			gSet := set.CreateStringSet(cred.Groups...)
			if gSet.Equals(currGroupsSet) {
				// No change to groups memberships for this
				// credential.
				continue
			}

			// Expired credentials don't need group membership updates.
			if cred.IsExpired() {
				continue
			}

			cred.Groups = currGroups