func (r Config) LookupUser(roleArn, userid string) (provider.User, error) {
	// Can safely ignore error here as empty or invalid ARNs will not be
	// mapped.
	arnVal, _ := arn.Parse(roleArn)
	pCfg, ok := r.arnProviderCfgsMap[arnVal]
	if ok {
		user, err := pCfg.provider.LookupUser(userid)
		if err != nil && err != provider.ErrAccessTokenExpired {
			return user, err
		}

		e.aggregate.runningCount++
		// Convert to float.
		f, ok := argVal.ToFloat()
		if !ok {
			return fmt.Errorf("Could not convert value %v (%s) to a number", argVal.value, argVal.GetTypeString())
		}
		argVal.setFloat(f)
		err = e.aggregate.runningSum.arithOp(opPlus, argVal)

	case aggFnMin:
		err = e.aggregate.runningMin.minmax(argVal, false, isFirstRow)

	case aggFnMax: