kubernetes/staging/src/k8s.io/client-go/tools/remotecommand/fallback.go

var _ …

type FallbackExecutor …

// NewFallbackExecutor creates an Executor that first attempts to use the
// WebSocketExecutor, falling back to the legacy SPDYExecutor if the initial
// websocket "StreamWithContext" call fails.
// func NewFallbackExecutor(config *restclient.Config, method string, url *url.URL) (Executor, error) {
func NewFallbackExecutor(primary, secondary Executor, shouldFallback func(error) bool) (Executor, error) { … }

// Stream is deprecated. Please use "StreamWithContext".
func (f *FallbackExecutor) Stream(options StreamOptions) error { … }

// StreamWithContext initially attempts to call "StreamWithContext" using the
// primary executor, falling back to calling the secondary executor if the
// initial primary call to upgrade to a websocket connection fails.
func (f *FallbackExecutor) StreamWithContext(ctx context.Context, options StreamOptions) error { … }