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: decoder.go
    path of file: ./repos/td/tdjson
    
    the code of the file until where you have to start completion: package tdjson

import (
	"encoding/base64"
	"encoding/hex"

	"github.com/go-faster/errors"
	"github.com/go-faster/jx"

	"github.com/gotd/td/bin"
)

// Decoder is a simple wrapper around jx.Decoder to conform TL type system.

    
func (b Decoder) Bytes() ([]byte, error) {
	// See https://core.telegram.org/tdlib/docs/td__json__client_8h.html
	//
	// ... fields of bytes type are base64 encoded and then stored as String ...
	enc := base64.RawStdEncoding

	v, err := b.Decoder.StrBytes()
	if err != nil {
		return nil, err
	}

	result := make([]byte, enc.DecodedLen(len(v)))
	if _, err := enc.Decode(result, v); err != nil {
		return nil, err
	}

	return result, nil
}