for i := 0; i < len(data); i++ {
			if data[i] == ',' {
				return i + 1, data[:i], nil
			}
		}
		if !atEOF {
			return 0, nil, nil
		}
		// There is one final token to be delivered, which may be the empty string.
		// Returning bufio.ErrFinalToken here tells Scan there are no more tokens after this
		// but does not trigger an error to be returned from Scan itself.
		return 0, data, bufio.ErrFinalToken
	}