old_contents: import Immutable from 'immutable'
  import { createSelector } from 'reselect'
  
  export const selectAnnouncementCollection = state => state.json.get('announcements', Immutable.Map())
  
  export const selectAnnouncement = createSelector(
    [selectAnnouncementCollection], collection =>
      collection.first() || Immutable.Map(),
  )
  
  export const selectIsAnnouncementUnread = createSelector(
    [selectAnnouncementCollection], collection => Boolean(collection && Object.keys(collection)[0]),
  )
  
  
new_contents: import Immutable from 'immutable'
  import { createSelector } from 'reselect'
  
  export const selectAnnouncementCollection = state => state.json.get('announcements', Immutable.Map())
  
  export const selectAnnouncement = createSelector(
    [selectAnnouncementCollection], collection =>
      collection.first() || Immutable.Map(),
  )
  
  export const selectIsAnnouncementUnread = createSelector(
    [selectAnnouncementCollection], collection => Boolean(collection && collection.size),
  )
  
  
subject: Use unread announcement lookup as Immutable object