code: private static Map<WriterKind, PrintWriter> initWriters(PrintWriter out, PrintWriter err) {
          Map<WriterKind, PrintWriter> writers = new EnumMap<>(WriterKind.class);
          writers.put(WriterKind.ERROR, err);
          writers.put(WriterKind.WARNING, err);
          writers.put(WriterKind.NOTICE, err);
  
          writers.put(WriterKind.STDOUT, out);
          writers.put(WriterKind.STDERR, err);
  
          return writers;
      }
docs: Initialize a writer map for a stream for normal output, and a stream for diagnostics.
  @param out a stream to be used for normal output
  @param err a stream to be used for diagnostic messages, such as errors, warnings, etc
  @return a map of writers