code: private void setAuthenticationHeaders(Object soapClient, AdManagerSession adManagerSession)
        throws AuthenticationException {
      authorizationHeaderHandler.setAuthorization(soapClient, adManagerSession);
    }
docs: Sets the authentication headers.
  
  @param soapClient the SOAP client
  @param adManagerSession the Ad Manager session
  @throws AuthenticationException if there was a problem getting/setting the header