# File lib/fog/ecloud/compute.rb, line 577
        def <<(disk)
          next_address = 0
          disk_with_max_address = max {|a, b| a[:address] <=> b[:address] }
          disk_with_max_address && next_address = disk_with_max_address.address + 1
          disk[:address] ||= next_address

          super(disk)

          if (addresses = map {|d| d.address }).uniq.size != size
            raise "Duplicate disk address in: #{addresses.inspect} (#{size})"
          end

          sort! {|a, b| a.address <=> b.address }
          self
        end