The new _iter_headers() method accesses self._segment but NoOpStreamedSpan does not initialize this attribute (it doesn't call super().__init__() and only sets _scope, _unsampled_reason, and _finished). In scope.py:688, span._iter_headers() is called without a guard against NoOpStreamedSpan, unlike _to_baggage() (line 607) and _get_trace_context() (line 621) which have not isinstance(self.span, NoOpStreamedSpan) checks. When iter_trace_propagation_headers() is called while a NoOpStreamedSpan is active, this will raise AttributeError: 'NoOpStreamedSpan' object has no attribute '_segment'.

In get_trace_context, line 620 checks self._span is not None but line 621 checks isinstance(self.span, NoOpStreamedSpan), mixing the private attribute with the public property. This is inconsistent with get_traceparent and get_baggage which consistently use self.span throughout. While currently functionally equivalent (since self.span just returns self._span), this inconsistency could cause subtle issues if the property behavior changes in the future.