code: @Beta
    public void writeLines(Stream<? extends CharSequence> lines) throws IOException {
      writeLines(lines, System.getProperty("line.separator"));
    }
docs: Writes the given lines of text to this sink with each line (including the last) terminated with
  the operating system's default line separator. This method is equivalent to {@code
  writeLines(lines, System.getProperty("line.separator"))}.
  
  @throws IOException if an I/O error occurs while writing to this sink
  @since 22.0