anchor.diff:  uuid_to_share_guid(FileUuid, SpaceId, undefined) ->
       uuid_to_guid(FileUuid, SpaceId);
   uuid_to_share_guid(FileUuid, undefined, ShareId) ->
  -    <<"shareGuid", "#", FileUuid/binary, "#", "#", ShareId/binary>>;
  +    <<?SHARE_GUID_PREFIX, ?GUID_SEPARATOR, FileUuid/binary,
  +        ?GUID_SEPARATOR,
  +        ?GUID_SEPARATOR, ShareId/binary
  +    >>;
   uuid_to_share_guid(FileUuid, SpaceId, ShareId) ->
  -    <<"shareGuid", "#", FileUuid/binary, "#", SpaceId/binary, "#", ShareId/binary>>.
  +    <<?SHARE_GUID_PREFIX, ?GUID_SEPARATOR,  FileUuid/binary,
  +        ?GUID_SEPARATOR, SpaceId/binary,
  +        ?GUID_SEPARATOR, ShareId/binary
  +    >>.
   
   %%--------------------------------------------------------------------
   %% @doc
  
positive.code: -export([guid_to_share_guid/2, share_guid_to_guid/1, is_share_guid/1,
      guid_to_share_id/1, guid_to_space_id/1]).
  
  %%%===================================================================
  %%% API
  %%%===================================================================
  
negative.code: %%--------------------------------------------------------------------
  -spec user_root_dir_uuid(UserId :: od_user:id()) -> file_meta:uuid().
  user_root_dir_uuid(UserId) ->
      <<?USER_ROOT_PREFIX, UserId/binary>>.
  
  %%--------------------------------------------------------------------
  %% @doc Returns Uuid of user's root directory.
  