is_null

<?php     protected function mapToFactory($key, $value = null): array

    {

        return [

            $key => is_null($value) ? $value : "'{$key}' => $value",

        ];

    }

<?php     protected function resolveModelPath(): string

    {

        $path = $this->option('path');

        if (!is_null($path)) {

            return base_path($path);

        }