private void startSession() {
GetSessionTokenResult sessionTokenResult = securityTokenService
.getSessionToken(new GetSessionTokenRequest().withDurationSeconds(DEFAULT_DURATION_SECONDS));
Credentials stsCredentials = sessionTokenResult.getCredentials();
sessionCredentials = new BasicSessionCredentials(
stsCredentials.getAccessKeyId(),
stsCredentials.getSecretAccessKey(),
stsCredentials.getSessionToken());
sessionCredentialsExpiration = stsCredentials.getExpiration();
}