code: public static void append(Path file, Writer writer, boolean writeBom) throws IOException {
          append(file, writer, Charset.defaultCharset().name(), writeBom);
      }
docs: Append the text supplied by the Writer at the end of the File, using a specified encoding.
  If the given charset is "UTF-16BE" or "UTF-16LE" (or an equivalent alias),
  <code>writeBom</code> is <code>true</code>, and the file doesn't already
  exist, the requisite byte order mark is written to the file before the
  text is appended.
  
  @param file     a File
  @param writer   the Writer supplying the text to append at the end of the File
  @param writeBom whether to write the BOM
  @throws IOException if an IOException occurs.
  @since 2.5.0