/**
  * Tests `Collection::closed` && `Collection::close`.
  */
 public function testClosed()
 {
     $collection = new DocumentSet();
     $this->assertTrue($collection->closed());
     $collection = new DocumentSet(array('result' => 'foo'));
     $this->assertFalse($collection->closed());
     $collection->close();
     $this->assertTrue($collection->closed());
 }