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: formatter.go
    path of file: ./repos/netbird/formatter
    
    the code of the file until where you have to start completion: package formatter

import (
	"fmt"
	"strings"
	"time"

	"github.com/sirupsen/logrus"
)

// TextFormatter formats logs into text with included source code's path
type TextFormatter struct {
	timestampFormat string
	levelDesc       []string
}

// NewTextFormatter create new MyTe
    
func (f *TextFormatter) Format(entry *logrus.Entry) ([]byte, error) {
	var fields string
	keys := make([]string, 0, len(entry.Data))
	for k, v := range entry.Data {
		if k == "source" {
			continue
		}
		keys = append(keys, fmt.Sprintf("%s: %v", k, v))
	}

	if len(keys) > 0 {
		fields = fmt.Sprintf("[%s] ", strings.Join(keys, ", "))
	}

	level := f.parseLevel(entry.Level)

	return []byte(fmt.Sprintf("%s %s %s%s: %s\n", entry.Time.Format(f.timestampFormat), level, fields, entry.Data["source"], entry.Message)), nil
}