Accessing Objects in Third-Party Systems

Using the code snippet found in "Accessing Objects in Third-Party Systems" section of the vSphere 5.5 Documentation Center, I found a problem I can't overcome. 

Code snippet (straight from the documentation):

URI uri = URI.create("https://orchestrator1:8283/vco/api");

    VcoSessionFactory sessionFactory = new DefaultVcoSessionFactory(uri);

    //provide the address of the vCenter Single Sign-On server

    URI ssoUri = URI.create("https://vCenter1:7444/ims/STSService?wsdl");

    //set the tokens to be valid for an hour

    long lifeTimeSeconds = 60 * 60;

    //create a factory for vCenter Single Sign-On tokens

    SsoAuthenticator sso = new SsoAuthenticator(ssoUri, sessionFactory, lifeTimeSeconds);

There is no class found in any of the vSphere or Orchestrator libraries that can be imported to handle the object "SsoAuthenticator".  My goal is to use this code to obtain the token needed to make REST API calls on Orchestrator to run workflows.  Any help in accomplishing my goal would be appreciated. 

As an aside, another approach to obtain the token using a SOAP call works (I used the AcquireBearerTokenByUserCredentialSample found in the documentation successfully); however, I thought I would ask the forum for insight on the whereabouts of the class associated with SsoAuthenticator in case there is something I am missing.