DiffOp example

use ExpectDeprecationTrait;
  use PhpUnitWarnings;

  /** * DiffOp::reverse() always throws an error. * * @covers ::reverse */
  public function testReverse() {
    $this->expectDeprecation('Drupal\Component\Diff\Engine\DiffOp::reverse() is deprecated in drupal:10.1.0 and is removed from drupal:11.0.0. There is no replacement. See https://www.drupal.org/node/3337942');
    $this->expectError();
    $op = new DiffOp();
    $result = $op->reverse();
  }

}