+
+ has_many :nodes
+ has_many :ways
+ has_many :relations
+ has_many :old_nodes
+ has_many :old_ways
+ has_many :old_relations
+
+ validates_presence_of :user_id, :created_at, :open
+
+ # Use a method like this, so that we can easily change how we
+ # determine whether a changeset is open, without breaking code in at
+ # least 6 controllers
+ def is_open?
+ return open
+ end