code: def copy(self):
          
          content = [(k, v) for k, v in self.items()]
  
          intidx = [(k, v) for k, v in content if isinstance(k, int)]
          args = [v for k, v in sorted(intidx)]
  
          kwargs = {k: v
                    for k, v in content
                    if not isinstance(k, int) and not self.is_special(k)}
          return self.__class__(*args, **kwargs)
docs: Return a copy of this `Fact`.