You are an expert in writing code in many different languages. Your goal is to perform code completion for the following code, keeping in mind the rest of the code and the file meta data.
    Metadata details:
    filename: email_change.go
    path of file: ./repos/client/go/engine
    
    the code of the file until where you have to start completion: // Copyright 2015 Keybase, Inc. All rights reserved. Use of
// this source code is governed by the included BSD license.

package engine

import (
	"github.com/keybase/client/go/libkb"
	keybase1 "github.com/keybase/client/go/protocol/keybase1"
	jsonw "github.com/keybase/go-jsonw"
)

// EmailChange is an engine that
    
func (c *EmailChange) Run(m libkb.MetaContext) (err error) {
	defer m.Trace("EmailChange#Run", &err)()

	if !libkb.CheckEmail.F(c.arg.NewEmail) {
		return libkb.BadEmailError{}
	}

	var me *libkb.User
	me, err = libkb.LoadMe(libkb.NewLoadUserArgWithMetaContext(m).WithForceReload())
	if err != nil {
		return err
	}

	// need unlocked signing key
	ska := libkb.SecretKeyArg{
		Me:      me,
		KeyType: libkb.DeviceSigningKeyType,
	}
	arg := m.SecretKeyPromptArg(ska, "tracking signature")
	signingKey, err := m.G().Keyrings.GetSecretKeyWithPrompt(m, arg)
	if err != nil {
		return err
	}
	if signingKey == nil {
		return libkb.NoSecretKeyError{}
	}
	var proof *jsonw.Wrapper
	proof, err = me.UpdateEmailProof(m, signingKey, c.arg.NewEmail)
	if err != nil {
		return err
	}
	var sig string
	sig, _, _, err = libkb.SignJSON(proof, signingKey)
	if err != nil {
		return err
	}

	_, err = m.G().API.Post(m, libkb.APIArg{
		Endpoint:    "account/email_update_signed",
		SessionType: libkb.APISessionTypeREQUIRED,
		Args: libkb.HTTPArgs{
			"sig":         libkb.S{Val: sig},
			"signing_kid": libkb.S{Val: signingKey.GetKID().String()},
		},
	})

	if err != nil {
		return err
	}

	return nil
}