/**
* Set birthday.
*
* @param integer $years Years.
*/
protected function setBirthday($years = 0)
{
$date = new \DateTime();
$this->birthday = $years ? self::$faker->dateTimeBetween('-' . $years . ' years', (int) $date->format('Y') - $years + 1 . '-01-01')->format('Y-m-d') : self::$faker->date('Y-m-d', '2002-01-01');
}