private function __construct()
 {
     define('ALLOW_PAGSEGURO_CONFIG', true);
     require_once PagSeguroLibrary::getPath() . DIRECTORY_SEPARATOR . "config" . DIRECTORY_SEPARATOR . "PagSeguroConfig.php";
     $varName = self::VARNAME;
     if (isset(${$varName})) {
         self::$data = ${$varName};
         unset(${$varName});
     } else {
         throw new Exception("Config is undefined.");
     }
 }
 private function __construct()
 {
     define('ALLOW_PAGSEGURO_CONFIG', true);
     if (!class_exists('PagSeguroConfigWrapper')) {
         require_once PagSeguroLibrary::getPath() . DIRECTORY_SEPARATOR . "config" . DIRECTORY_SEPARATOR . "PagSeguroConfigWrapper.php";
     }
     $wrapper = new PagSeguroConfigWrapper();
     if (method_exists($wrapper, 'getConfig')) {
         self::$data = $wrapper->getConfig();
     } else {
         throw new Exception("Config is undefined.");
     }
 }