code: public UnsafeMappedBytes map(long offset, long size) {
      return map(offset, size, FileChannel.MapMode.READ_WRITE);
    }
docs: Maps a portion of the randomAccessFile into memory in {@link java.nio.channels.FileChannel.MapMode#READ_WRITE} mode and returns
  a {@link UnsafeMappedBytes} instance.
  
  @param offset The offset from which to map the randomAccessFile into memory.
  @param size The count of the bytes to map into memory.
  @return The mapped bytes.
  @throws IllegalArgumentException If {@code count} is greater than the maximum allowed
  {@link java.nio.MappedByteBuffer} count: {@link Integer#MAX_VALUE}