code: def _from_frame(cls, frame):
          "Copy constructor"
          assert frame._framespec == cls._framespec
          new = cls(flags=frame.flags, frameno=frame.frameno)
          for spec in cls._framespec:
              setattr(new, spec.name, getattr(frame, spec.name, None))
          return nef _from_frame(cls, frame):
          "Copy constructor"
          assert frame._framespec == cls._framespec
          new = cls(flags=frame.flags, frameno=frame.frameno)
          for spec in cls._framespec:
              setattr(new, spec.name, getattr(frame, spec.name, None))
          return new
docs: Copy constructor