public function shouldAddVersionOnMasspayCall()
{
$api = new Api(array('username' => 'a_username', 'password' => 'a_password', 'signature' => 'a_signature', 'sandbox' => true), $this->createSuccessHttpClientStub(), $this->createHttpMessageFactory());
$result = $api->massPay([]);
$this->assertArrayHasKey('VERSION', $result);
$this->assertEquals(Api::VERSION, $result['VERSION']);
}