public function testSetMashapeKey()
{
Request::setMashapeKey('abcd');
$response = Request::get('http://mockbin.com/request');
$this->assertEquals(200, $response->code);
$this->assertTrue(property_exists($response->body->headers, 'x-mashape-key'));
$this->assertEquals('abcd', $response->body->headers->{'x-mashape-key'});
// send another request
$response = Request::get('http://mockbin.com/request');
$this->assertEquals(200, $response->code);
$this->assertTrue(property_exists($response->body->headers, 'x-mashape-key'));
$this->assertEquals('abcd', $response->body->headers->{'x-mashape-key'});
Request::clearDefaultHeaders();
$response = Request::get('http://mockbin.com/request');
$this->assertEquals(200, $response->code);
$this->assertFalse(property_exists($response->body->headers, 'x-mashape-key'));
}