Doctrine\MongoDB\Query\Expr::in PHP Method

    public function in(array $values)
    {
        return $this->operator('$in', array_values($values));
    }

 /**
  * Specify $in criteria for the current field.
  *
  * @see Expr::in()
  * @see http://docs.mongodb.org/manual/reference/operator/in/
  * @param array $values
  * @return self
  */
 public function in(array $values)
 {
     $this->expr->in($values);
     return $this;
 }