guava/src/com/google/common/io/CharSink.java
@Beta
  public void writeLines(Stream<? extends CharSequence> lines) throws IOException {
    writeLines(lines, System.getProperty("line.separator"));
  }
@Beta
  public void writeLines(Stream<? extends CharSequence> lines) throws IOException {
    writeLines(lines, System.getProperty("line.separator"));
  }
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