body := issue18239Body{&readCallsAtomic, &closeCallsAtomic, someErr}

	req, err := NewRequest("POST", ts.URL, body)
	if err != nil {
		t.Fatal(err)
	}
	req = req.WithT(t)
	_, err = tr.RoundTrip(req)
	if err != someErr {
		t.Errorf("Got error: %v; want Request.Body read error: %v", err, someErr)
	}

	// And verify that our Body wasn't used multiple times, which

			default:
			}
			pc.cancelRequest(context.Cause(req.ctx))
		}
	}
}

// tLogKey is a context WithValue key for test debugging contexts containing
// a t.Logf func. See export_test.go's Request.WithT method.
type tLogKey struct{}

func (tr *transportRequest) logf(format string, args ...any) {
	if logf, ok := tr.Request.Context().Value(tLogKey{}).(func(string, ...any)); ok {