The new StreamedSpan handling at line 903 unconditionally sets self._transaction = span.name without checking if the name is truthy. In contrast, the Transaction handling (line 891-892) only sets _transaction when transaction.name is truthy. If a StreamedSpan has an empty name, this would set _transaction = "", which would later populate the event transaction with an empty string (line 1654-1655), whereas with Transaction, the _transaction would remain unchanged.