anchor.diff:          Class:Error ->
               {error, {Class, {Error, erlang:get_stacktrace()}}}
       end.
  -
   
   
   %% @doc Safe gen_server:call/3
  
positive.code: -spec to_map(list()|map()) -> 
      map().
  
  to_map(M) when is_map(M) -> M;
  to_map(L) when is_list(L) -> maps:from_list(L).
  
  
  %% @doc Converts anything into a `integer()' or `error'.
  
negative.code: 
  
  %% @doc Like gen_server:call/3 but traps exceptions
  %% For timeouts: {error, {exit, {timeout, _}}}
  -spec call(atom()|pid(), term(), #{timeout=>pos_integer()|infinity}) ->
      term() | {error, timeout | {exit|error|throw, {term(), list()}}}.
  
  call(Dest, Msg, Opts) ->
      Timeout = maps:get(timeout, Opts, 5000),
  