in src/main/java/org/opensearch/commons/rest/SecureRestClientBuilder.java [247:254]
private CredentialsProvider createCredsProvider() {
if (Strings.isNullOrEmpty(user) || Strings.isNullOrEmpty(passwd))
return null;
final CredentialsProvider credentialsProvider = new BasicCredentialsProvider();
credentialsProvider.setCredentials(AuthScope.ANY, new UsernamePasswordCredentials(user, passwd));
return credentialsProvider;
}