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: ini_lexer.go
    path of file: ./repos/plumber/vendor/github.com/aws/aws-sdk-go/internal/ini
    
    the code of the file until where you have to start completion: package ini

import (
	"bytes"
	"io"
	"io/ioutil"

	"github.com/aws/aws-sdk-go/aws/awserr"
)

const (
	// ErrCodeUnableToReadFile is used when a file is failed to be
	// opened or read from.
	ErrCodeUnableToReadFile = "FailedRead"
)

// TokenType represents the various different tokens types
type TokenType int

func (t TokenType) String() string {
	switch t {
	case TokenNone:
		return "none"
	case TokenLit:
		return "literal"
	case TokenSep:
		return "sep"
	case TokenOp:
		return "op"
	case TokenWS:
		return "ws"
	case TokenNL:
		retur
    
func countTokens(runes []rune) int {
	count, n := 0, 0
	var err error

	for len(runes) > 0 {
		switch {
		case isWhitespace(runes[0]):
			_, n, err = newWSToken(runes)
		case isComma(runes[0]):
			_, n = newCommaToken(), 1
		case isComment(runes):
			_, n, err = newCommentToken(runes)
		case isNewline(runes):
			_, n, err = newNewlineToken(runes)
		case isSep(runes):
			_, n, err = newSepToken(runes)
		case isOp(runes):
			_, n, err = newOpToken(runes)
		default:
			_, n, err = newLitToken(runes)
		}

		if err != nil {
			return 0
		}

		count++
		runes = runes[n:]
	}

	return count + 1
}