    private function filterPort($scheme, $host, $port)
    {
        if (null !== $port) {
            $port = (int) $port;
            if (1 > $port || 0xffff < $port) {
                throw new \InvalidArgumentException(
                    sprintf('Invalid port: %d. Must be between 1 and 65535', $port)
                );
            }
        }

        return $this->isNonStandardPort($scheme, $host, $port) ? $port : null;
    }
The software constructs all or part of an SQL command using externally-influenced input from an upstream component, but it does not neutralize or incorrectly neutralizes special elements that could modify the intended SQL command when it is sent to a downstream component.