Traceback (most recent call last):
  File "header_class_raw.py", line 5, in <module>
    msg['Subject'] = Header('"Michael Müller" <mm@example.org>', 'utf-8')
    ~~~^^^^^^^^^^^
  File "cpython@3.13.2/lib/python3.13/email/message.py", line 441, in __setitem__
    self._headers.append(self.policy.header_store_parse(name, val))
                         ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^^^^^^^^^^^
  File "cpython@3.13.2/lib/python3.13/email/policy.py", line 148, in header_store_parse
    return (name, self.header_factory(name, value))
                  ~~~~~~~~~~~~~~~~~~~^^^^^^^^^^^^^
  File "cpython@3.13.2/lib/python3.13/email/headerregistry.py", line 604, in __call__
    return self[name](name, value)
           ~~~~~~~~~~^^^^^^^^^^^^^
  File "cpython@3.13.2/lib/python3.13/email/headerregistry.py", line 192, in __new__
    cls.parse(value, kwds)
    ~~~~~~~~~^^^^^^^^^^^^^
  File "cpython@3.13.2/lib/python3.13/email/headerregistry.py", line 267, in parse
    kwds['parse_tree'] = cls.value_parser(value)
                         ~~~~~~~~~~~~~~~~^^^^^^^
  File "cpython@3.13.2/lib/python3.13/email/_header_value_parser.py", line 1130, in get_unstructured
    if value[0] in WSP:
       ~~~~~^^^
TypeError: 'Header' object is not subscriptable