cst := newClientServerTest(t, mode, HandlerFunc(func(w ResponseWriter, r *Request) {
		w.WriteHeader(StatusNotModified)
		_, err := w.Write([]byte("illegal body"))
		if err != ErrBodyNotAllowed {
			t.Errorf("on Write, expected ErrBodyNotAllowed, got %v", err)
		}
	}))
	defer cst.close()
	res, err := cst.c.Get(cst.ts.URL)
	if err != nil {
		t.Fatal(err)
	}
	if len(res.TransferEncoding) > 0 {

	"sync/atomic"
	"time"
	_ "unsafe" // for linkname

	"golang.org/x/net/http/httpguts"
)

// Errors used by the HTTP server.
var (
	// ErrBodyNotAllowed is returned by ResponseWriter.Write calls
	// when the HTTP method or response code does not permit a
	// body.
	ErrBodyNotAllowed = errors.New("http: request method or response status code does not allow body")

	// ErrHijacked is returned by ResponseWriter.Write calls when

	rws := w.rws
	if rws == nil {
		panic("Write called after Handler finished")
	}
	if !rws.wroteHeader {
		w.WriteHeader(200)
	}
	if !http2bodyAllowedForStatus(rws.status) {
		return 0, ErrBodyNotAllowed
	}
	rws.wroteBytes += int64(len(dataB)) + int64(len(dataS)) // only one can be set
	if rws.sentContentLen != 0 && rws.wroteBytes > rws.sentContentLen {
		// TODO: send a RST_STREAM

		{"DefaultMaxIdleConnsPerHost", Const, 0},
		{"DefaultServeMux", Var, 0},
		{"DefaultTransport", Var, 0},
		{"DetectContentType", Func, 0},
		{"Dir", Type, 0},
		{"ErrAbortHandler", Var, 8},
		{"ErrBodyNotAllowed", Var, 0},
		{"ErrBodyReadAfterClose", Var, 0},
		{"ErrContentLength", Var, 0},
		{"ErrHandlerTimeout", Var, 0},
		{"ErrHeaderTooLong", Var, 0},
		{"ErrHijacked", Var, 0},
		{"ErrLineTooLong", Var, 0},

pkg net/http, type Transport struct, TLSClientConfig *tls.Config
pkg net/http, var DefaultClient *Client
pkg net/http, var DefaultServeMux *ServeMux
pkg net/http, var DefaultTransport RoundTripper
pkg net/http, var ErrBodyNotAllowed error
pkg net/http, var ErrBodyReadAfterClose error
pkg net/http, var ErrContentLength error
pkg net/http, var ErrHandlerTimeout error
pkg net/http, var ErrHeaderTooLong *ProtocolError