code: func Initialize(c context.Context, cfg *Config) context.Context {
  	if getConfig(c) != nil {
  		panic("auth.Initialize is called twice on same context")
  	}
  	return setConfig(c, cfg)
  }
docs: // Initialize inserts authentication configuration into the context.
  //
  // An initialized context is required by any other function in the package. They
  // return ErrNotConfigured otherwise.
  //
  // Calling Initialize twice causes a panic.