+ belongs_to :changeset
+ belongs_to :redaction
+ belongs_to :current_way, :class_name => "Way", :foreign_key => "way_id"
+
+ has_many :old_nodes, :class_name => "OldWayNode", :foreign_key => [:way_id, :version]
+ has_many :old_tags, :class_name => "OldWayTag", :foreign_key => [:way_id, :version]
+
+ validates :changeset, :presence => true, :associated => true
+ validates :timestamp, :presence => true
+ validates :visible, :inclusion => [true, false]