code: def _load(self, name, workdir, quiet=False):
          
  
          ## load the JSON string and try with name+.json
          path = os.path.join(workdir, name)
          if not path.endswith(".tet.json"):
              path += ".tet.json"
  
          ## expand user
          path = path.replace("~", os.path.expanduser("~"))
  
          ## load the json file as a dictionary
          try:
              with open(path, 'r') as infile:
                  fullj = _byteify(json.loads(infile.read(),
                                  object_hook=_byteify), 
                              ignore_dicts=True)
          except IOError:
              raise IPyradWarningExit("""\
          Cannot find checkpoint (.tet.json) file at: {}""".format(path))
  
          ## set old attributes into new tetrad object
          self.name = fullj["name"]
          self.files.data = fullj["files"]["data"]
          self.files.mapfile = fullj["files"]["mapfile"]        
          self.dirs = fullj["dirs"]
          self._init_seqarray(quiet=quiet)
          self._parse_names()
  
          ## fill in the same attributes
          for key in fullj:
              ## fill Params a little different
              if key in ["files", "params", "database", 
                         "trees", "stats", "checkpoint"]:
                  filler = fullj[key]
                  for ikey in filler:
                      self.__dict__[key].__setattr__(ikey, fullj[key][ikey])
              else:
                  self.__setattr__(key, fullj[key])
docs: Load a JSON serialized tetrad instance to continue from a checkpoint.