+ validates :id, :uniqueness => true, :presence => { :on => :update },
+ :numericality => { :on => :update, :integer_only => true }
+ validates :user_id, :presence => true,
+ :numericality => { :integer_only => true }
+ validates :num_changes, :presence => true,
+ :numericality => { :integer_only => true,
+ :greater_than_or_equal_to => 0 }
+ validates :created_at, :closed_at, :presence => true
+ validates :min_lat, :max_lat, :min_lon, :max_lat, :allow_nil => true,
+ :numericality => { :integer_only => true }