/**
  * setting and retrieving owner of a file
  *
  * @test
  * @group  permissions
  */
 public function owner()
 {
     $this->assertEquals(vfsStream::getCurrentUser(), $this->file->getUser());
     $this->assertTrue($this->file->isOwnedByUser(vfsStream::getCurrentUser()));
     $this->assertSame($this->file, $this->file->chown(vfsStream::OWNER_USER_1));
     $this->assertEquals(vfsStream::OWNER_USER_1, $this->file->getUser());
     $this->assertTrue($this->file->isOwnedByUser(vfsStream::OWNER_USER_1));
 }