public function pow($number, $exponent) : self
    {
        $this->expr->pow($number, $exponent);

        return $this;
    }
public function pow($number, $exponent) : self
    {
        $this->expr->pow($number, $exponent);

        return $this;
    }
public function pow ( $ number , $ exponent ) : self { $ this -> expr -> pow ( $ number , $ exponent ) ; return $ this ; }
Raises a number to the specified exponent and returns the result.

The <number> expression can be any valid expression as long as it
resolves to a non-negative number.
The <exponent> expression can be any valid expression as long as it
resolves to a number.

@see https://docs.mongodb.org/manual/reference/operator/aggregation/pow/
@see Expr::pow

@param mixed|Expr $number
@param mixed|Expr $exponent
Raises a number to the specified exponent and returns the result .