public AwsTemporaryCredentials get() {
        if(shouldRefresh(credentials)) {
            this.credentials = ztsClient.getAwsTemporaryCredentials(athenzDomain, awsRole, expiryOrNull, externalId);
        }
        return credentials;
    }
Requests temporary credentials from ZTS or return cached credentials
vespa-athenz/src/main/java/com/yahoo/vespa/athenz/aws/AwsCredentials.java