:numericality => { :on => :update, :only_integer => true }
validates :version, :presence => true,
:numericality => { :only_integer => true }
- validates :changeset_id, :presence => true,
- :numericality => { :only_integer => true }
validates :timestamp, :presence => true
validates :changeset, :associated => true
validates :visible, :inclusion => [true, false]