code: private function loadDotEnv($isExample = false)
      {
          // make sure all environment clear.
          $this->emptyEnvironment();
  
          // load the .env(.example) file to environment
          $postfix = $isExample ? '.example' : '';
          try {
              Dotenv::load(base_path(), self::ENV . $postfix);
          } catch (InvalidArgumentException $e) {
              // if the .env file not found then return empty array
              if (!$isExample) {
                  return [];
              }
              throw $e;
          }
          return $_ENV;
      }
docs: Load the .env(.example) file
  @param  boolean $isExample
  @return array