anchor.diff:              error_badepoch;
           error_trimmed ->
               %% TODO: robustify
  -            [ok = case corfurl_flu:trim(flu_pid(X), Epoch, LPN) of
  -                      ok ->            ok;
  -                      error_trimmed -> ok;
  -                      Else          -> Else
  +            [ok = case ok_or_trim(corfurl_flu:trim(flu_pid(X), Epoch, LPN)) of
  +                      ok              -> ok;
  +                      error_unwritten -> ok_or_trim(corfurl_flu:fill(
  +                                                      flu_pid(X), Epoch, LPN));
  +                      Else            -> Else
                     end || X <- Rest],
               error_trimmed;
           error_unwritten ->
  
positive.code: flu_pid(X) when is_atom(X) ->
      ets:lookup_element(flu_pid_tab, X, 1).
  
  %%%% %%%% %%%%    projection utilities    %%%% %%%% %%%%
  
  new_range(Start, End, ChainList) ->
  
negative.code:                     %% TODO: same TODO as the above error_badepoch case.
                      error_badepoch;
                  Else ->
                      giant_error({left_off_here, ?MODULE, ?LINE, Else})
              end
      end.
  
  