Doctrine\MongoDB\Aggregation\Stage\Operator::add PHP Method

add() public method

The arguments can be any valid expression as long as they resolve to either all numbers or to numbers and a date.
See also: http://docs.mongodb.org/manual/reference/operator/aggregation/add/
See also: Expr::add
public add ( mixed | Expr $expression1, mixed | Expr $expression2 )
$expression1 mixed | Doctrine\MongoDB\Aggregation\Expr
$expression2 mixed | Doctrine\MongoDB\Aggregation\Expr
    public function add($expression1, $expression2)
    {
        $this->expr->add(...func_get_args());
        return $this;
    }