# File lib/blimpy/securitygroups.rb, line 6
    def self.group_id(ports)
      if ports.nil? or ports.empty?
        return nil
      end

      unless ports.is_a? Set
        ports = Set.new(ports)
      end

      # Lolwut, #hash is inconsistent between ruby processes
      "Blimpy-#{Zlib.crc32(ports.inspect)}"
    end