Improve docs

filters/featureBreaker/gi.go

-// Copyright 2015 The Chromium Authors. All rights reserved.
-// Use of this source code is governed by a BSD-style license that can be
-// found in the LICENSE file.
-
-package featureBreaker
-
-import (
-        "time"
-
-        "golang.org/x/net/context"
-
-        "github.com/luci/gae/service/info"
-)
-
-type infoState struct {
-        *state
-
-        info.Interface
-}
-
-func (g *infoState) ModuleHostname(module, version, instance string) (ret string, err error) {
-        err = g.run(func() (err error) {
-                ret, err = g.Interface.ModuleHostname(module, version, instance)
-                return
-        })
-        return
-}
-
-func (g *infoState) ServiceAccount() (ret string, err error) {
-        err = g.run(func() (err error) {
-                ret, err = g.Interface.ServiceAccount()
-                return
-        })
-        return
-}
-
-func (g *infoState) Namespace(namespace string) (ret context.Context, err error) {
-        err = g.run(func() (err error) {
-                ret, err = g.Interface.Namespace(namespace)
-                return
-        })
-        return
-}
-
-func (g *infoState) AccessToken(scopes ...string) (token string, expiry time.Time, err error) {
-        err = g.run(func() (err error) {
-                token, expiry, err = g.Interface.AccessToken(scopes...)
-                return
-        })
-        return
-}
-
-func (g *infoState) PublicCertificates() (ret []info.Certificate, err error) {
-        err = g.run(func() (err error) {
-                ret, err = g.Interface.PublicCertificates()
-                return
-        })
-        return
-}
-
-func (g *infoState) SignBytes(bytes []byte) (keyName string, signature []byte, err error) {
-        err = g.run(func() (err error) {
-                keyName, signature, err = g.Interface.SignBytes(bytes)
-                return
-        })
-        return
-}
-
-// FilterGI installs a counter info filter in the context.
-func FilterGI(c context.Context, defaultError error) (context.Context, FeatureBreaker) {
-        state := newState(defaultError)
-        return info.AddFilters(c, func(ic context.Context, i info.Interface) info.Interface {
-                return &infoState{state, i}
-        }), state
-}