/**
  * @dataProvider provider_sampleMinusWeeksSymmetry
  * @group long
  */
 public function test_minusWeeks_symmetry(LocalDateTime $reference)
 {
     for ($weeks = 0; $weeks < 365 * 8; $weeks++) {
         $t = $reference->minusWeeks($weeks)->minusWeeks(-$weeks);
         $this->assertEquals($t, $reference);
         $t = $reference->minusWeeks(-$weeks)->minusWeeks($weeks);
         $this->assertEquals($t, $reference);
     }
 }