class Server {

public function getUsers( ) {
            $retorno        =   file_get_contents('php://input');
            return $retorno;
        }

$oSoapServer    =   new SoapServer(NULL, array( 'uri' => 'http://local.com.br/soap/' ) );
    $oSoapServer->setClass("Server");
    $oSoapServer->handle();

ini_set("soap.wsdl_cache_enabled", "0");
$options    = array(
      'location'    =>  'http://local.com.br/soap/server.php?wsdl',
      'uri'     =>  'http://local.com.br/soap/'
    );
    $oSoapClient    = new SoapClient(NULL,$options);

$Auth           = new stdClass();
    $Auth->SystemId = "DATA";
    $Auth->UserName = "USERNAME";
    $Auth->Password = "PASSWORD";

    $auth_object    = new SoapVar($Auth, SOAP_ENC_OBJECT);
    $header         = new SoapHeader('http://local.com.br/soap/', 'Authorization', $auth_object);

    $oSoapClient->__setSoapHeaders($header);

echo "<pre>";

    /* Executing a fuction, for example isAlive method */
    $response = $oSoapClient->__soapCall("getUsers", array($auth_object));
    // $xml = simplexml_load_string($response);
    var_dump($response);
    echo "</pre>";