public function testExporterGetSet()
{
$graph = new Graph();
$exporter = $graph->getExporter();
$this->assertInstanceOf('Fhaculty\\Graph\\Exporter\\ExporterInterface', $exporter);
// multiple calls should return the same exporter
$this->assertSame($exporter, $graph->getExporter());
$graph->setExporter($exporter);
}