code: def _update_names(self):
          
  
          d = dict(
              table=self.table_name,
              time=self.time,
              space=self.space,
              grain=self.grain,
              variant=self.variant,
              segment=self.segment
          )
  
          assert self.dataset
  
          name = PartialPartitionName(**d).promote(self.dataset.identity.name)
  
          self.name = str(name.name)
          self.vname = str(name.vname)
          self.cache_key = name.cache_key
          self.fqname = str(self.identity.fqname)
docs: Update the derived names