/**
  * @covers ::convert
  */
 public function testConvert()
 {
     if (!class_exists('\\DateTimeImmutable')) {
         return;
     }
     $test1 = Converter::convert(Calends::create(0, 'unix'));
     $this->assertEquals(['start' => new DateTimeImmutable('@0'), 'duration' => new DateInterval('PT0S'), 'end' => new DateTimeImmutable('@0')], $test1);
     $test2 = Converter::convert(Calends::create(['start' => 0, 'end' => 86400], 'unix'));
     $this->assertEquals(['start' => new DateTimeImmutable('@0'), 'duration' => new DateInterval('PT86400S'), 'end' => new DateTimeImmutable('@86400')], $test2);
 }