equality.rb

module Equality
  include ActiveSupport::Concern

  def ==(other)
    if self.instance_variables == other.instance_variables
      self.instance_variables.each do |ivar|
        return false if self.instance_variable_get(ivar) != self.instance_variable_get(ivar)
      end
      true
    else
      false
    end
  end
end

visitor.rb

class Visitor
  include ActiveModel::Model
  include Equality
end