var token = new OAuthToken.Builder()
.clientID(clientId from self client)
.clientSecret(client secret from the self client)
.grantToken(the generated code) .build();
var moduleOperations = new ModulesOperations();
var headerInstance = new HeaderMap();
var ifmodifiedsince = OffsetDateTime.of(2020, 05, 20, 10, 00, 00, 01, ZoneOffset.of("+05:30"));
headerInstance.add(ModulesOperations.GetModulesHeader.IF_MODIFIED_SINCE, ifmodifiedsince);
var response = moduleOperations.getModules(headerInstance);