code: public AccessToken refreshAccessToken(AccessToken accessToken, Scope... scopes) {
          return getAuthService().refreshAccessToken(accessToken, scopes);
      }
docs: Provides a new and refreshed access token by getting the refresh token from the given access token.
  
  @param accessToken the access token to be refreshed
  @param scopes      an optional parameter if the scope of the token should be changed. Otherwise the scopes of the
  old token are used.
  @return the new access token with the refreshed lifetime
  @throws IllegalArgumentException          in case the accessToken has an empty refresh token
  @throws ConnectionInitializationException if the connection to the given OSIAM service could not be initialized
  @throws UnauthorizedException             if the request could not be authorized.
  @throws IllegalStateException             if OSIAM's endpoint(s) are not properly configured