class Aws::S3::FileDownloader

def compute_mode(file_size, count)
  chunk_size = compute_chunk(file_size)
  part_size = (file_size.to_f / count.to_f).ceil
  if chunk_size < part_size
    multithreaded_get_by_ranges(construct_chunks(file_size))
  else
    multithreaded_get_by_parts(count)
  end
end