- .. note:: As this iterates over the tags, we will not be able
- to iterate over them again (as in retrieve them)! If
- the tags have been exhausted already, this will raise a
- :exc:`NotmuchError` STATUS.NOT_INITIALIZED on
- subsequent attempts.
- """
- if self._tags is None:
- raise NotmuchError(STATUS.NOT_INITIALIZED)
+ If __nonzero__ is not implemented, "if Tags()"
+ will implicitly call __len__, using up our iterator, so it is
+ important that this function is defined.