code: @Beta
    public static MappedByteBuffer map(File file, MapMode mode, long size) throws IOException {
      checkArgument(size >= 0, "size (%s) may not be negative", size);
      return mapInternal(file, mode, size);
    }
docs: Maps a file in to memory as per {@link FileChannel#map(java.nio.channels.FileChannel.MapMode,
  long, long)} using the requested {@link MapMode}.
  
  <p>Files are mapped from offset 0 to {@code size}.
  
  <p>If the mode is {@link MapMode#READ_WRITE} and the file does not exist, it will be created
  with the requested {@code size}. Thus this method is useful for creating memory mapped files
  which do not yet exist.
  
  <p>This only works for files ≤ {@link Integer#MAX_VALUE} bytes.
  
  @param file the file to map
  @param mode the mode to use when mapping {@code file}
  @return a buffer reflecting {@code file}
  @throws IOException if an I/O error occurs
  @see FileChannel#map(MapMode, long, long)
  @since 2.0