app/resources/activity_resource.rb
class ActivityResource < BaseResource
include ScopelessResource
model_name 'Feed::Activity'
attributes :status, :verb, :time, :stream_id, :foreign_id, :rating,
:progress, :reply_to_type, :reply_to_user, :nineteen_scale, :mentioned_users, :reason
has_one :actor, polymorphic: true, eager_load_on_include: false
has_one :unit, polymorphic: true, eager_load_on_include: false
has_one :media, polymorphic: true, eager_load_on_include: false
has_one :subject, polymorphic: true, eager_load_on_include: false
has_one :target, polymorphic: true, eager_load_on_include: false
end