public function testDefaultHeaders()
{
$defaultHeaders = array('header1' => 'Hello', 'header2' => 'world');
Request::defaultHeaders($defaultHeaders);
$response = Request::get('http://mockbin.com/request');
$this->assertEquals(200, $response->code);
$this->assertObjectHasAttribute('header1', $response->body->headers);
$this->assertEquals('Hello', $response->body->headers->header1);
$this->assertObjectHasAttribute('header2', $response->body->headers);
$this->assertEquals('world', $response->body->headers->header2);
$response = Request::get('http://mockbin.com/request', ['header1' => 'Custom value']);
$this->assertEquals(200, $response->code);
$this->assertObjectHasAttribute('header1', $response->body->headers);
$this->assertEquals('Custom value', $response->body->headers->header1);
Request::clearDefaultHeaders();
$response = Request::get('http://mockbin.com/request');
$this->assertEquals(200, $response->code);
$this->assertObjectNotHasAttribute('header1', $response->body->headers);
$this->assertObjectNotHasAttribute('header2', $response->body->headers);
}