GrumPHP\IO\ConsoleIO::doWrite PHP Method

    private function doWrite($messages, $newline, $stderr)
    {
        if (true === $stderr && $this->output instanceof ConsoleOutputInterface) {
            $this->output->getErrorOutput()->write($messages, $newline);
            return;
        }
        $this->output->write($messages, $newline);
    }