docs: def _finalize(self):
          """
          Finalizes the request.
          """
          if len(self.all_successors) == 0:
              return
  
          # do some cleanup
          if o.DOWNSIZE_Z3 in self.all_successors[0].options:
              for s in self.all_successors:
                  s.downsize()
  
          # record if the exit is unavoidable
          if len(self.flat_successors) == 1 and len(self.unconstrained_successors) == 0:
              self.flat_successors[0].scratch.avoidable = False