anchor.diff:  -type error_m(X) :: X|{error, any()}.
   
   % Number of seconds between beginning of gregorian calendar and 1970
  --define(GREGORIAN_SECONDS_1970, 62167219200). 
  +-define(GREGORIAN_SECONDS_1970, 62167219200).
   -compile(export_all).
   -ifdef(TEST).
   -compile(export_all).
  
positive.code:     end.
  -spec(read_connect1(read_mode(), mongo:rs_connection()) ->
  	     error_m( mongo:connection())).
        
  read_connect1(master, RSConn) ->
       mongo_replset:primary(RSConn);
  read_connect1(slave_ok, RSConn) ->
  
negative.code:         {ok, ok}			-> {ok, Record};
          {ok, Id}			-> {ok, Record:set(id, unpack_id(Type, Id))};
          {failure, Reason}		-> {error, Reason}
  
      end.
  
  execute_save_record(Conn, Record, Collection, DefinedId) ->
  