code: func NewTokenHandler(transport http.RoundTripper, creds CredentialStore, scope string, actions ...string) AuthenticationHandler {
  	// Create options...
  	return NewTokenHandlerWithOptions(TokenHandlerOptions{
  		Transport:   transport,
  		Credentials: creds,
  		Scopes: []Scope{
  			RepositoryScope{
  				Repository: scope,
  				Actions:    actions,
  			},
  		},
  	})
  }
docs: // NewTokenHandler creates a new AuthenicationHandler which supports
  // fetching tokens from a remote token server.