public function log($number, $base) : self
    {
        $this->expr->log($number, $base);

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

        return $this;
    }
public function log ( $ number , $ base ) : self { $ this -> expr -> log ( $ number , $ base ) ; return $ this ; }
Calculates the log of a number in the specified base and returns the
result as a double.

The <number> expression can be any valid expression as long as it
resolves to a non-negative number.
The <base> expression can be any valid expression as long as it resolves
to a positive number greater than 1.

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

@param mixed|Expr $number
@param mixed|Expr $base
Calculates the log of a number in the specified base and returns the result as a double .