TypeError: 'bool' object is not iterable

[2022-05-04 10:52:20,160: ERROR/ForkPoolWorker-21] Task rabotnikobm.assembly.run_task[b377fb93-20db-4e8a-ada7-ddd0c11ef65c] raised unexpected: TypeError("'bool' object is not iterable")
Traceback (most recent call last):
  File "/Users/mariuskriegerowski/src/gfz/rabotnik/rabotnik-obm/venv/lib/python3.9/site-packages/celery/app/trace.py", line 451, in trace_task
    R = retval = fun(*args, **kwargs)
  File "/Users/mariuskriegerowski/src/gfz/rabotnik/rabotnik-obm/venv/lib/python3.9/site-packages/celery/app/trace.py", line 734, in __protected_call__
    return self.run(*args, **kwargs)
  File "/Users/mariuskriegerowski/src/gfz/rabotnik/rabotnik-obm/venv/lib/python3.9/site-packages/rabotnikobm/assembly.py", line 29, in run_task
    rule.evaluate(building_id)
  File "/Users/mariuskriegerowski/src/gfz/rabotnik/rabotnik-obm/venv/lib/python3.9/site-packages/rabotnikobm/rules/gem_occupancy/get_gem_occupancy.py", line 364, in evaluate
    tags = GetGEMBuildingOccupancy.fetch_tags(building_id)
  File "/Users/mariuskriegerowski/src/gfz/rabotnik/rabotnik-obm/venv/lib/python3.9/site-packages/rabotnikobm/rules/gem_occupancy/get_gem_occupancy.py", line 359, in fetch_tags
    tags.extend(fetcher.evaluate(building_id=building_id))
TypeError: 'bool' object is not iterable