}
	})

	t.Run("Persistence", func(t *testing.T) {
		tw := NewWriter(new(failOnceWriter))
		if err := tw.WriteHeader(&Header{}); err != io.ErrShortWrite {
			t.Fatalf("WriteHeader() = %v, want %v", err, io.ErrShortWrite)
		}
		if err := tw.WriteHeader(&Header{Name: "small.txt"}); err == nil {
			t.Errorf("WriteHeader() = got %v, want non-nil error", err)
		}
		if _, err := tw.Write(nil); err == nil {

	return blobBody
}

// WriteHeader - writes http status code
func (lrw *ResponseRecorder) WriteHeader(code int) {
	if !lrw.headersLogged {
		lrw.ttfbHeader = time.Now().UTC().Sub(lrw.StartTime)
		lrw.StatusCode = code
		lrw.writeHeaders(&lrw.headers, code, lrw.ResponseWriter.Header())
		lrw.headersLogged = true
		lrw.ResponseWriter.WriteHeader(code)
	}
}

// Flush - Calls the underlying Flush.

		return tw.err
	}
	tw.pad = 0
	return nil
}

// WriteHeader writes hdr and prepares to accept the file's contents.
// The Header.Size determines how many bytes can be written for the next file.
// If the current file is not fully written, then this returns an error.
// This implicitly flushes any padding necessary before writing the header.
func (tw *Writer) WriteHeader(hdr *Header) error {
	if err := tw.Flush(); err != nil {
		return err

			if contextCanceled(ctx) {
				w.WriteHeader(499)
				return
			}
			f.ServeHTTP(w, r)
		case <-r.Context().Done():
			globalHTTPStats.addRequestsInQueue(-1)
			// When the client disconnects before getting the S3 handler
			// status code response, set the status code to 499 so this request
			// will be properly audited and traced.
			w.WriteHeader(499)
		default:

			// If the object ETag matches with the specified ETag.
			writeHeaders()
			writeErrorResponse(ctx, w, errorCodes.ToAPIErr(ErrPreconditionFailed), r.URL)
			return true
		}
	}

	etagMatch := opts.PreserveETag != "" && isETagEqual(objInfo.ETag, opts.PreserveETag)
	vidMatch := opts.VersionID != "" && opts.VersionID == objInfo.VersionID
	if etagMatch && vidMatch {
		writeHeaders()

		}
		fw.rawCount = &countWriter{w: fw.comp}
		fw.header = h
		ow = fw
	}
	w.dir = append(w.dir, h)
	if err := writeHeader(w.cw, h); err != nil {
		return nil, err
	}
	// If we're creating a directory, fw is nil.
	w.last = fw
	return ow, nil
}

func writeHeader(w io.Writer, h *header) error {
	const maxUint16 = 1<<16 - 1
	if len(h.Name) > maxUint16 {
		return errLongName
	}

// Some fields may not be populated.
//
// For forward compatibility, users that retrieve a Header from Reader.Next,
// mutate it in some ways, and then pass it back to Writer.WriteHeader
// should do so by creating a new Header and copying the fields
// that they are interested in preserving.
type Header struct {
	// Typeflag is the type of header entry.

	testServer := httptest.NewServer(http.HandlerFunc(func(res http.ResponseWriter, req *http.Request) {
		cniAddServerCalled = true
		if serverErr {
			res.WriteHeader(http.StatusInternalServerError)
			res.Write([]byte("server not happy"))
			return
		}
		res.WriteHeader(http.StatusOK)
		res.Write([]byte("server happy"))
	}))

	// replace the global CNI client with mock

			case <-ticker.C:
				if !started {
					// Start writing response to client
					started = true
					setCommonHeaders(w)
					setEventStreamHeaders(w)
					// Set 200 OK status
					w.WriteHeader(200)
				}
				// Send whitespace and keep connection open
				if _, err := w.Write([]byte(" ")); err != nil {
					return
				}
				w.(http.Flusher).Flush()
			case hr := <-respCh:

		bugLogIf(context.Background(), fmt.Errorf("invalid WriteHeader code %v", statusCode))
		statusCode = http.StatusInternalServerError
	}
	setCommonHeaders(w)
	if mType != mimeNone {
		w.Header().Set(xhttp.ContentType, string(mType))
	}
	w.Header().Set(xhttp.ContentLength, strconv.Itoa(len(response)))
	w.WriteHeader(statusCode)
	if response != nil {
		w.Write(response)
	}
}