code: protected static function resolveInstance($facadeName)
      {
          if (is_object($facadeName)) {
              return $facadeName;
          }
  
          if (isset(static::$resolvedInstance[$facadeName])) {
              return static::$resolvedInstance[$facadeName];
          }
  
          return static::$resolvedInstance[$facadeName] = static::$app->get($facadeName);
      }
docs: Resolved Instance
  
  @param string $facadeName
  @return string