read_chunked

# File lib/net/http.rb, line 2766
    def read_chunked(dest)
      len = nil
      total = 0
      while true
        line = @socket.readline
        hexlen = line.slice(/[0-9a-fA-F]+/) or
            raise HTTPBadResponse, "wrong chunk size line: #{line}"
        len = hexlen.hex
        break if len == 0
        begin
          @socket.read len, dest
        ensure
          total += len
          @socket.read 2   # \r\n
        end
      end
      until @socket.readline.empty?
        # none
      end
    end