code: func effectiveLen(line string) int {
  	effectiveBytes := 0
  	for _, rune := range line {
  		effectiveBytes += utf8.RuneLen(rune)
  	}
  	return effectiveBytes
  }
docs: // effectiveLen counts the effective number of bytes in the string, after
  // UTF-8 normalization.  UTF-8 normalization includes replacing bytes that do
  // not constitute valid UTF-8 encoded Unicode codepoints with the Unicode
  // replacement codepoint U+FFFD (a 3-byte UTF-8 sequence, represented in Go as
  // utf8.RuneError)