class Async::HTTP::Body::File

def initialize(file, range = nil, block_size: BLOCK_SIZE)
	@file = file
	
	@block_size = block_size
	
	if range
		@file.seek(range.min)
		@offset = range.min
		@length = @remaining = range.size
	else
		@offset = 0
		@length = @remaining = @file.size
	end
end