def extend_hit(self, hit_id, number, duration_hours=None):
self.create_additional_assignments_for_hit(hit_id, number)<EOL>if duration_hours is not None:<EOL><INDENT>self.update_expiration_for_hit(hit_id, duration_hours)<EOL><DEDENT>return self.get_hit(hit_id)<EOL>
Extend an existing HIT and return an updated description