code: public String generateToken(String sessionId) throws OpenTokException {
          return generateToken(sessionId, new TokenOptions.Builder().build());
      }
docs: Creates a token for connecting to an OpenTok session, using the default settings. The default
  settings are the following:
  
  <ul>
  <li>The token is assigned the role of publisher.</li>
  <li>The token expires 24 hours after it is created.</li>
  <li>The token includes no connection data.</li>
  </ul>
  
  <p>
  The following example shows how to generate a token that has the default settings:
  <p>
  <pre>
  import com.opentok.OpenTok;
  
  class Test {
  public static void main(String argv[]) throws OpenTokException {
  int API_KEY = 0; // Replace with your OpenTok API key (see https://tokbox.com/account).
  String API_SECRET = ""; // Replace with your OpenTok API secret.
  OpenTok sdk = new OpenTok(API_KEY, API_SECRET);
  
  //Generate a basic session. Or you could use an existing session ID.
  String sessionId = System.out.println(sdk.createSession().getSessionId());
  
  String token = sdk.generateToken(sessionId);
  System.out.println(token);
  }
  }
  </pre>
  @param sessionId The session ID corresponding to the session to which the user will connect.
  
  @return The token string.
  
  @see #generateToken(String, TokenOptions)