app/models/err.rb
# Represents a set of Notices which can be automatically
# determined to refer to the same Error (Errbit groups
# notices into errs by a notice's fingerprint.)
class Err < ActiveRecord::Base
belongs_to :problem, :inverse_of => :errs
has_many :notices, :inverse_of => :err, :dependent => :destroy
validates_presence_of :problem, :fingerprint
delegate :app, :resolved?, :to => :problem
end