public function testRetrieve()
 {
     self::authorizeFromEnv();
     $receiver = $this->createTestBitcoinReceiver("*****@*****.**");
     $r = Stripe_BitcoinReceiver::retrieve($receiver->id);
     $this->assertEqual($receiver->id, $r->id);
     $this->assertIsA($r->transactions->data[0], 'Stripe_BitcoinTransaction');
 }