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: encoder.go
    path of file: ./repos/devspace/vendor/gopkg.in/src-d/go-git.v4/plumbing/format/index
    
    the code of the file until where you have to start completion: package index

import (
	"bytes"
	"crypto/sha1"
	"errors"
	"hash"
	"io"
	"sort"
	"time"

	"gopkg.in/src-d/go-git.v4/utils/binary"
)

var (
	// EncodeVersionSupported is the range of supported index versions
	EncodeVersionSupported uint32 = 2

	// ErrInvalidTimestamp is returned by Encode if a Index with a Entry with
	// negative timestamp values
	ErrInvalidTimestamp = errors.New("negative timestamps are not
    
func (e *Encoder) encodeEntry(entry *Entry) error {
	if entry.IntentToAdd || entry.SkipWorktree {
		return ErrUnsupportedVersion
	}

	sec, nsec, err := e.timeToUint32(&entry.CreatedAt)
	if err != nil {
		return err
	}

	msec, mnsec, err := e.timeToUint32(&entry.ModifiedAt)
	if err != nil {
		return err
	}

	flags := uint16(entry.Stage&0x3) << 12
	if l := len(entry.Name); l < nameMask {
		flags |= uint16(l)
	} else {
		flags |= nameMask
	}

	flow := []interface{}{
		sec, nsec,
		msec, mnsec,
		entry.Dev,
		entry.Inode,
		entry.Mode,
		entry.UID,
		entry.GID,
		entry.Size,
		entry.Hash[:],
		flags,
	}

	if err := binary.Write(e.w, flow...); err != nil {
		return err
	}

	return binary.Write(e.w, []byte(entry.Name))
}