pkg net, type Dialer struct, DualStack //deprecated
pkg net/http, method (*Transport) CancelRequest //deprecated
pkg net/http, type CloseNotifier //deprecated
pkg net/http, type ProtocolError //deprecated
pkg net/http, type Request struct, Cancel //deprecated
pkg net/http, type Transport struct, Dial //deprecated
pkg net/http, type Transport struct, DialTLS //deprecated
pkg net/http, var ErrHeaderTooLong //deprecated

pkg math/bits, func Rem64(uint64, uint64, uint64) uint64
pkg mime/multipart, method (*Reader) NextRawPart() (*Part, error)
pkg net/http, method (Header) Values(string) []string
pkg net/http, type Transport struct, DialTLSContext func(context.Context, string, string) (net.Conn, error)
pkg net/http/httptest, type Server struct, EnableHTTP2 bool
pkg net/textproto, method (MIMEHeader) Values(string) []string

behavior has changed based on a non-default value
for that setting.
For example, when `GODEBUG=http2client=0` is set,
`/godebug/non-default-behavior/http2client:events`
counts the number of HTTP transports that the program
has configured without HTTP/2 support.

## Default GODEBUG Values {#default}

When a GODEBUG setting is not listed in the environment variable,
its value is derived from three sources:

pkg net/http, method (*ResponseController) SetWriteDeadline(time.Time) error #54136
pkg net/http, type ResponseController struct #54136
pkg net/http, type Server struct, DisableGeneralOptionsHandler bool #41773
pkg net/http, type Transport struct, OnProxyConnectResponse func(context.Context, *url.URL, *Request, *Response) error #54299
pkg net/netip, func IPv6LinkLocalAllRouters() Addr #51766
pkg net/netip, func IPv6Loopback() Addr #51777