app/bundles/LeadBundle/Tests/Entity/CompanyTest.php

<?php

namespace Mautic\LeadBundle\Tests\Entity;

use Mautic\LeadBundle\Entity\Company;

class CompanyTest extends \PHPUnit\Framework\TestCase
{
    public function testChangingPropertiesHydratesFieldChanges(): void
    {
        $email    = '[email protected]';
        $company  = new Company();
        $company->addUpdatedField('email', $email);
        $changes = $company->getChanges();

        $this->assertFalse(empty($changes['fields']['email']));

        $this->assertEquals($email, $changes['fields']['email'][1]);
    }
}