Inspects an ``Entry`` instance, and builds associates ``Tag``
        objects based on the values in the ``Entry``'s ``tag_string``.

def create_tags(self, entry):
        """Inspects an ``Entry`` instance, and builds associates ``Tag``
        objects based on the values in the ``Entry``'s ``tag_string``."""
        tag_list = [t.lower().strip() for t in entry.tag_string.split(',')]
        for t in tag_list:
            tag, created = self.get_or_create(name=t)
            entry.tags.add(tag)