class Customer < CassandraObject::Base
      attribute :first_name,    :type => :string
      attribute :last_name,     :type => :string
      attribute :date_of_birth, :type => :date
      attribute :signed_up_at,  :type => :time_with_zone

      validate :should_be_cool

      key :uuid

      index :date_of_birth

      association :invoices, :unique=>false, :inverse_of=>:customer

      private

      def should_be_cool
        unless ["Michael", "Anika", "Evan", "James"].include?(first_name)
          errors.add(:first_name, "must be that of a cool person")
        end
      end
    end

    class Invoice < CassandraObject::Base
      attribute :number, :type=>:integer
      attribute :total, :type=>:float
      attribute :gst_number, :type=>:string

      # indexes can have a single entry also.
      index :number, :unique=>true

      # bi-directional associations with read-repair support.
      association :customer, :unique=>true, :inverse_of=>:invoices

      # Read migration support
      migrate 1 do |attrs|
        attrs["total"] ||= rand(2000) / 100.0
      end

      migrate 2 do |attrs|
        attrs["gst_number"] = "66-666-666"
      end

      key :natural, :attributes => :number
    end
    
    @invoice = Invoice.get("12345")
    @invoice.customer.invoices.all.include?(@invoice) # true