wantWasmModule := "wasm\n"
			ts = httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
				c.handler(w, r, gotNumRequest)
				gotNumRequest++
			}))
			defer ts.Close()
			fetcher := NewHTTPFetcher(DefaultHTTPRequestTimeout, DefaultHTTPRequestMaxRetries)
			fetcher.initialBackoff = time.Microsecond
			ctx, cancel := context.WithTimeout(context.Background(), c.timeout)
			defer cancel()

	insecureClient  *http.Client
	initialBackoff  time.Duration
	requestMaxRetry int
}

// NewHTTPFetcher create a new HTTP remote wasm module fetcher.
// requestTimeout is a timeout for each HTTP/HTTPS request.
// requestMaxRetry is # of maximum retries of HTTP/HTTPS requests.
func NewHTTPFetcher(requestTimeout time.Duration, requestMaxRetry int) *HTTPFetcher {
	if requestTimeout == 0 {
		requestTimeout = 5 * time.Second

	wasmLog.Debugf("LocalFileCache is created with the option\n%#v", options)

	cacheOptions := cacheOptions{Options: options}
	cache := &LocalFileCache{
		httpFetcher:  NewHTTPFetcher(options.HTTPRequestTimeout, options.HTTPRequestMaxRetries),
		modules:      make(map[moduleKey]*cacheEntry),
		checksums:    make(map[string]*checksumEntry),
		dir:          dir,
		cacheOptions: cacheOptions.sanitize(),