code: func GetConfig(c *caddy.Controller) *Config {
  	ctx := c.Context().(*dnsContext)
  	if cfg, ok := ctx.keysToConfigs[c.Key]; ok {
  		return cfg
  	}
  	// we should only get here during tests because directive
  	// actions typically skip the server blocks where we make
  	// the configs.
  	ctx.saveConfig(c.Key, &Config{})
  	return GetConfig(c)
  }
docs: // GetConfig gets the Config that corresponds to c.
  // If none exist nil is returned.