for input.Scan() {
		line := strings.TrimSpace(input.Text())
		if line == "" {
			continue
		}
		// Find first separator.
		idx := strings.IndexByte(line, trailerKVSeparator[0])
		if idx <= 0 || idx >= len(line) {
			if cr.debug {
				fmt.Printf("Could not find separator, got %q\n", line)
			}
			return errMalformedEncoding
		}
		key := strings.ToLower(line[:idx])