161         # new markers to serialize

   161         # new markers to serialize

   162         self._new = []

   162         self._new = []

   163         self.precursors = {}

   163         self.precursors = {}

   164         self.successors = {}

   164         self.successors = {}

   165 

   165 

   166     def create(self, prec, succs=(), flag=0, metadata=None):

   169     def create(self, prec, succs=(), flag=0, metadata=None):

   167         """obsolete: add a new obsolete marker

   170         """obsolete: add a new obsolete marker

   168 

   171 

   169         * ensuring it is hashable

   172         * ensuring it is hashable

   170         * check mandatory metadata

   173         * check mandatory metadata

   216             format = _fmfixed + (_fmnode * nbsuc)

   219             format = _fmfixed + (_fmnode * nbsuc)

   217             data = [nbsuc, len(metadata), flags, pre]

   220             data = [nbsuc, len(metadata), flags, pre]

   218             data.extend(sucs)

   221             data.extend(sucs)

   219             stream.write(_pack(format, *data))

   222             stream.write(_pack(format, *data))

   220             stream.write(metadata)

   223             stream.write(metadata)