code: public UnsafeMappedBytes map(long offset, long size, FileChannel.MapMode mode) {
      return new UnsafeMappedBytes(file, new MappedMemoryAllocator(randomAccessFile, mode, offset).allocate(size));
    }
docs: Maps a portion of the randomAccessFile into memory 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.
  @param mode The mode in which to map the randomAccessFile 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}