code: func processLine(d *Directive, token []byte, stripLeftWhitespace bool) ([]byte, error) {
  	if stripLeftWhitespace {
  		token = trimWhitespace(token)
  	}
  	return trimComments(token), d.possibleParserDirective(string(token))
  }
docs: // TODO: remove stripLeftWhitespace after deprecation period. It seems silly
  // to preserve whitespace on continuation lines. Why is that done?