code: static void close(boolean delete) {
          if (openedFile != null) {
              out.close();
              out = System.err;
  
              if (delete) {
                  openedFile.delete();
              }
          }
      }
docs: Close the debug log opened by {@link #open} and optionally delete it.
  This method has no effect if {@link #open} was not called successfully.
  
  @param delete true if the debug log should be deleted after closing