code: public static BufferedWriter newWriter(Path self, boolean append) throws IOException {
          if (append) {
              return Files.newBufferedWriter(self, Charset.defaultCharset(), CREATE, APPEND);
          }
          return Files.newBufferedWriter(self, Charset.defaultCharset());
      }
docs: Creates a buffered writer for this file, optionally appending to the
  existing file content.
  
  @param self   a Path
  @param append true if data should be appended to the file
  @return a BufferedWriter
  @throws java.io.IOException if an IOException occurs.
  @since 2.3.0