anchor.diff:  
       revision_history = [] :: [subscriptions:rev()]
   }).
  -
   
   %% Model for caching handle details fetched from OZ
   -record(od_handle, {
  
positive.code:     users :: undefined | sets:set(od_user:id())
  }).
  
  
  %% Identity containing user_id
  -record(user_identity, {
      user_id :: undefined | od_user:id(),
      provider_id :: undefined | oneprovider:id()
  }).
  
  
  %% User session
  -record(session, {
  
negative.code:     file_uuids = [] :: [file_meta:uuid()]
  }).
  
  %% Model for holding current quota state for spaces
  -record(space_quota, {
      current_size = 0 :: non_neg_integer()
  }).
  
  %% Record that holds monitoring id
  -record(monitoring_id, {
  