public function testError() {
		$base = Libraries::get(true, 'resources') . '/tmp/tests';
		$this->skipIf(!is_writable($base), "Path `{$base}` is not writable.");

		$response = new Response(array('error' => fopen($this->streams['error'], 'w+')));
		$this->assertTrue(is_resource($response->error));
		$this->assertEqual(2, $response->error('ok'));
		$this->assertEqual('ok', file_get_contents($this->streams['error']));
	}