code: def get_strategy(name_or_cls):
      
      if isinstance(name_or_cls, six.string_types):
          if name_or_cls not in STRATS:
              raise MutationError("strat is not defined")
          return STRATS[name_or_cls]()
  
      return name_or_cls()
docs: Return the strategy identified by its name. If ``name_or_class`` is a class,
      it will be simply returned.