code: public static Promise<Void> writeNewFile(Executor executor, Path path, ByteBuf buf) {
  		return openAsync(executor, path, set(WRITE, CREATE_NEW))
  				.then(file -> file.write(buf)
  						.then($ -> file.close()))
  				.whenException($ -> buf.recycle());
  	}
docs: Creates new file and writes a sequence of bytes to this file from
  the given buffer, starting at the given file position.
  If file already exists, promise fails with exception.
  
  @param path the path of the file to create and write
  @param buf  the buffer from which bytes are to be transferred byteBuffer