/**
  * Signs request - adds Authorization header with generated value
  *
  * @param Paysera_WalletApi_Http_Request $request
  * @param array                          $parameters
  */
 public function signRequest(Paysera_WalletApi_Http_Request $request, array $parameters = array())
 {
     $request->setClientCertificate(clone $this->clientCertificate);
     foreach ($parameters as $name => $value) {
         $name = implode('-', array_map('ucfirst', explode('-', str_replace('_', '-', $name))));
         $request->setHeader(self::HEADER_PREFIX . $name, $value);
     }
 }