public function doRequest($uri, $body, $method = 'POST')
 {
     $auth = new \Bpi\Sdk\Authorization('200100', md5('agency_200100_public'), sha1('agency_200100_secret'));
     $client = static::createClient();
     $headers = array('HTTP_Content_Type' => 'application/vnd.bpi.api+xml', 'HTTP_Auth' => $auth->toHTTPHeader());
     $client->request($method, $uri, array(), array(), $headers, $body);
     return $client;
 }
 public function doRequest($http_accept, $file_extension)
 {
     $client = static::createClient();
     $headers = $http_accept ? array('HTTP_ACCEPT' => $http_accept) : array();
     $auth = new \Bpi\Sdk\Authorization('200100', md5('agency_200100_public'), sha1('agency_200100_secret'));
     $headers['HTTP_Auth'] = $auth->toHTTPHeader();
     $client->request('GET', '/tools/echo' . $file_extension, array(), array(), $headers);
     return $client;
 }