anchor.diff:  
       revision_history = [] :: [subscriptions:rev()]
   }).
  -
   
   %% Model for caching space details fetched from OZ
   -record(od_space, {
  
positive.code: 
      revision_history = [] :: [subscriptions:rev()]
  }).
  
  
  %% Model for caching handle details fetched from OZ
  -record(od_handle, {
  
negative.code:     active_descriptors = #{} :: active_descriptors()
  }).
  
  %% Model that holds file's custom metadata
  -record(custom_metadata, {
      space_id :: undefined | od_space:id(),
      value = #{} :: maps:map()
  }).
  
  %% Model that holds database views
  -record(indexes, {
      value = #{} :: indexes_value()
  }).
  
  %% Model that keeps track of consistency of file metadata
  -record(file_consistency, {
  