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: signature.go
    path of file: ./repos/erda/internal/tools/gittar/pkg/gitmodule
    
    the code of the file until where you have to start completion: // Copyright 2015 The Gogs Authors. All rights reserved.
// Use of this source code is governed by a MIT-style
// license that can be foun
    
func newSignatureFromCommitline(line []byte) (_ *Signature, err error) {
	sig := new(Signature)
	emailStart := bytes.IndexByte(line, '<')
	sig.Name = string(line[:emailStart-1])
	emailEnd := bytes.IndexByte(line, '>')
	sig.Email = string(line[emailStart+1 : emailEnd])

	// Check date format.
	firstChar := line[emailEnd+2]
	if firstChar >= 48 && firstChar <= 57 {
		timestop := bytes.IndexByte(line[emailEnd+2:], ' ')
		timestring := string(line[emailEnd+2 : emailEnd+2+timestop])
		seconds, _ := strconv.ParseInt(timestring, 10, 64)
		sig.When = time.Unix(seconds, 0)
	} else {
		sig.When, err = time.Parse("Mon Jan _2 15:04:05 2006 -0700", string(line[emailEnd+2:]))
		if err != nil {
			return nil, err
		}
	}
	return sig, nil
}