code: def _get_dynamic_base(self, bases_):
          
          bases = tuple(
              base.bases[0] if base.is_dynamic() else base for base in bases_
          )
  
          if len(bases) == 1:
              return bases[0]
  
          elif len(bases) > 1:
              return self.model.get_dynamic_base(bases)
  
          else:
              RuntimeError("must not happen")
docs: Create or get the base space from a list of spaces
  
          if a direct base space in `bases` is dynamic, replace it with
          its base.