public function loadEnvironment($env_file) 
    {
        $env_file .= '.php';
        if (!file_exists($env_file)) {
            return $this;
        }
        /** @noinspection PhpIncludeInspection */
        $environments = (array)include($env_file);
        foreach ($environments as $env) {
            $this->configure($this->config_dir . "/{$env}/configure");
        }
        return $this;
    }