public function testAuthorizationHeaderBuilder()
 {
     $key = new Key('e7fe97fa-a0c8-4a42-ab8e-2c26d52df059', 'bXlzZWNyZXRzZWNyZXR0aGluZ3Rva2VlcA==');
     $headers = ['X-Authorization-Timestamp' => '1432075982', 'Content-Type' => 'application/json'];
     $request = new Request('POST', 'http://example.com?test=true', $headers, 'body text');
     $builder = new AuthorizationHeaderBuilder($request, $key);
     $builder->setId($key->getId());
     $builder->setNonce('a9938d07-d9f0-480c-b007-f1e956bcd027');
     $builder->setVersion('2.0');
     $header = $builder->getAuthorizationHeader();
     $this->assertEquals($header->getId(), $key->getId());
     $this->assertEquals($header->getSignature(), 'f9G/Xu339hw1z2zHTOrHKNv1kWqvYHYI9Nu/phO5dPY=');
     $builder->setSignature('test');
     $header = $builder->getAuthorizationHeader();
     $this->assertEquals($header->getSignature(), 'test');
 }