code: func (dk *lazyDockerKeyring) Lookup(image string) ([]docker.AuthConfiguration, bool) {
  	keyring := &BasicDockerKeyring{}
  
  	for _, p := range dk.Providers {
  		keyring.Add(p.Provide())
  	}
  
  	return keyring.Lookup(image)
  }
docs: // Lookup implements the DockerKeyring method for fetching credentials
  // based on image name.