lib/Doctrine/MongoDB/Query/Expr.php
public function mul($value)
    {
        $this->requiresCurrentField();
        $this->newObj['$mul'][$this->currentField] = $value;
        return $this;
    }
public function mul($value)
    {
        $this->requiresCurrentField();
        $this->newObj['$mul'][$this->currentField] = $value;
        return $this;
    }
public function mul ( $ value ) { $ this -> requiresCurrentField ( ) ; $ this -> newObj [ '$mul' ] [ $ this -> currentField ] = $ value ; return $ this ; }
Multiply the current field.

If the field does not exist, it will be set to 0.

@see Builder::mul()
@see http://docs.mongodb.org/manual/reference/operator/mul/
@param float|integer $value
@return $this
Multiply the current field .