In HTTP 1.1 range has the form "[lower]-[upper]", so "[lower]-" is
valid. I'm not sure what range= takes, you get to try it
I found that its "Range: bytes=10000-", something like this. I wonder if
I can use this header to download the same file from different mirrors
i.e. have several
req = Net::HTTP::Get.new(path)
but with different ranges and write them to the same file with random
access. Would it be a right technique for this idea?