/**
* Adds an "or" expression to the current query.
*
* You can create the expression using the expr() method:
*
* $qb = $this->createQueryBuilder('User');
* $qb
* ->addOr($qb->expr()->field('first_name')->equals('Kris'))
* ->addOr($qb->expr()->field('first_name')->equals('Chris'));
*
*/