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: strftime.go
    path of file: ./repos/gotosocial/vendor/github.com/ncruces/go-strftime
    
    the code of the file until where you have to start completion: package strftime

import (
	"bytes"
	"strconv"
	"time"
)

// Format returns a textual representation of the time value
// formatted according to the strftime format specification.
func Format(fmt string, t time.Time) string {
	buf := buffer(fmt)
	return string(AppendFormat(buf, fmt, t))
}

// 
    
func UTS35(fmt string) (string, error) {
	const quote = '\''
	var quoted bool
	dst := buffer(fmt)

	var parser parser

	parser.literal = func(b byte) error {
		if b == quote {
			dst = append(dst, quote, quote)
			return nil
		}
		if !quoted && ('a' <= b && b <= 'z' || 'A' <= b && b <= 'Z') {
			dst = append(dst, quote)
			quoted = true
		}
		dst = append(dst, b)
		return nil
	}

	parser.format = func(spec, flag byte) error {
		if quoted {
			dst = append(dst, quote)
			quoted = false
		}
		if pattern := uts35Pattern(spec, flag); pattern != "" {
			dst = append(dst, pattern...)
			return nil
		}
		return formatError{}
	}

	if err := parser.parse(fmt); err != nil {
		return "", err
	}
	if quoted {
		dst = append(dst, quote)
	}
	return string(dst), nil
}