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: main.go
    path of file: ./repos/minio/docs/debugging/xl-meta
    
    the code of the file until where you have to start completion: // Copyright (c) 2015-2021 MinIO, Inc.
//
// This file is part of MinIO Object Storage stack
//
// This program is free software: you can redistribute it and/or modify
// it under the terms of the GNU Affero General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// This program is distributed in the hope that it will be useful
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU Affero General Public License for more details.
//
// You should have received a copy of the GNU Affero General Public License
// along with this program.  If not, see <http://www.gnu.org/licenses/>.

package main

import (
	"bytes"
	"encoding/binary"
	"encoding/hex"
	"encoding/json"
	"errors"
	"fmt"
	"io"
	"log"
	"os"
	"path/filepath"
	"sort"
	"strings"
	"time"

    
func combine(files []string, out string) error {
	sort.Strings(files)
	var size, shards, data, parity int
	mapped := make([]byte, size)
	filled := make([]byte, size)
	parityData := make(map[int]map[int][]byte)
	fmt.Printf("Attempting to combine version %q.\n", out)
	for _, file := range files {
		b, err := os.ReadFile(file)
		if err != nil {
			return err
		}
		meta, err := os.ReadFile(file + ".json")
		if err != nil {
			return err
		}
		type erasureInfo struct {
			V2Obj *struct {
				EcDist  []int
				EcIndex int
				EcM     int
				EcN     int
				Size    int
			}
		}
		var ei erasureInfo
		var idx int
		if err := json.Unmarshal(meta, &ei); err == nil && ei.V2Obj != nil {
			if size == 0 {
				size = ei.V2Obj.Size
				mapped = make([]byte, size)
				filled = make([]byte, size)
			}
			data = ei.V2Obj.EcM
			parity = ei.V2Obj.EcN
			if shards == 0 {
				shards = data + parity
			}
			idx = ei.V2Obj.EcIndex - 1
			fmt.Println("Read shard", ei.V2Obj.EcIndex, "Data shards", data, "Parity", parity, fmt.Sprintf("(%s)", file))
			if ei.V2Obj.Size != size {
				return fmt.Errorf("size mismatch. Meta size: %d", ei.V2Obj.Size)
			}
		} else {
			return err
		}
		if len(b) < 32 {
			return fmt.Errorf("file %s too short", file)
		}
		// Trim hash. Fine for inline data, since only one block.
		b = b[32:]

		set := parityData[data]
		if set == nil {
			set = make(map[int][]byte)
		}
		set[idx] = b
		parityData[data] = set

		// Combine
		start := len(b) * idx
		if start >= len(mapped) {
			continue
		}
		copy(mapped[start:], b)
		for j := range b {
			if j+start >= len(filled) {
				break
			}
			filled[j+start] = 1
		}
	}

	lastValid := 0
	missing := 0
	for i := range filled {
		if filled[i] == 1 {
			lastValid = i
		} else {
			missing++
		}
	}
	if missing > 0 && len(parityData) > 0 {
		fmt.Println("Attempting to reconstruct using parity sets:")
		for k, v := range parityData {
			if missing == 0 {
				break
			}
			fmt.Println("* Setup: Data shards:", k, "- Parity blocks:", len(v))
			rs, err := reedsolomon.New(k, shards-k)
			if err != nil {
				return err
			}
			split, err := rs.Split(mapped)
			if err != nil {
				return err
			}
			splitFilled, err := rs.Split(filled)
			if err != nil {
				return err
			}
			ok := len(splitFilled)
			for i, sh := range splitFilled {
				for _, v := range sh {
					if v == 0 {
						split[i] = nil
						ok--
						break
					}
				}
			}
			hasParity := 0
			for idx, sh := range v {
				split[idx] = sh
				if idx >= k && len(v) > 0 {
					hasParity++
				}
			}
			fmt.Printf("Have %d complete remapped data shards and %d complete parity shards. ", ok, hasParity)

			if err := rs.ReconstructData(split); err == nil {
				fmt.Println("Could reconstruct completely")
				for i, data := range split[:k] {
					start := i * len(data)
					copy(mapped[start:], data)
				}
				lastValid = size - 1
				missing = 0
			} else {
				fmt.Println("Could NOT reconstruct:", err)
			}
		}
	}
	if lastValid == 0 {
		return errors.New("no valid data found")
	}
	if missing > 0 {
		out += ".truncated"
	} else {
		out += ".complete"
	}
	fmt.Println(missing, "bytes missing. Truncating", len(filled)-lastValid-1, "from end.")
	mapped = mapped[:lastValid+1]
	err := os.WriteFile(out, mapped, os.ModePerm)
	if err != nil {
		return err
	}
	fmt.Println("Wrote output to", out)
	return nil
}