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: passphrase_check.go
    path of file: ./repos/client/go/engine
    
    the code of the file until where you have to start completion: // Copyright 2019 Keybase, Inc. All rights reserved. Use of
// this source code is governed by the included BSD license.

package engine

import (
	"errors"

	"github.com/keybase/client/go/libkb"
	keybase1 "github.com/keybase/client/go/protocol/keybase1"
)

// PassphraseCheck is an engine that checks if given passphrase matches curr
    
func (c *PassphraseCheck) Run(mctx libkb.MetaContext) (err error) {
	defer mctx.Trace("PassphraseCheck#Run", &err)()

	passphrase := c.arg.Passphrase
	if passphrase == "" {
		username := c.G().GetEnv().GetUsername().String()
		promptArg := libkb.DefaultPassphrasePromptArg(mctx, username)
		if !mctx.UIs().HasUI(libkb.SecretUIKind) {
			return errors.New("Passphrase was not passed in arguments and SecretUI is not available")
		}
		res, err := mctx.UIs().SecretUI.GetPassphrase(promptArg, nil)
		if err != nil {
			return err
		}
		passphrase = res.Passphrase
	}

	_, err = libkb.VerifyPassphraseForLoggedInUser(mctx, passphrase)
	if err != nil {
		if _, ok := err.(libkb.PassphraseError); ok {
			// Swallow passphrase errors, return `false` that the passphrase
			// provided was incorrect.
			c.result = false
			return nil
		}
		// There was some other error.
		return err
	}
	// No error, passphrase was correct.
	c.result = true
	return nil
}