Hey! The draw_all_flows utility fails when there's HITL (basically whenever there is an InputRequiredEvent)
```
File /opt/anaconda3/envs/llamaindex/lib/python3.12/site-packages/llama_index/utils/workflow/draw.py:62, in draw_all_possible_flows(workflow, filename, notebook)
60 for return_type in step_config.return_types:
61 if return_type != type(None):
---> 62 net.add_edge(step_name, return_type.__name__)
64 for event_type in step_config.accepted_events:
65 net.add_edge(event_type.__name__, step_name)
File /opt/anaconda3/envs/llamaindex/lib/python3.12/site-packages/pyvis/network.py:372, in Network.add_edge(self, source, to, **options)
368 # verify nodes exists
369 assert source in self.get_nodes(), \
370 "non existent node '" + str(source) + "'"
--> 372 assert to in self.get_nodes(), \
373 "non existent node '" + str(to) + "'"
375 # we only check existing edge for undirected graphs
376 if not self.directed:
AssertionError: non existent node 'InputRequiredEvent'