Handled possible unclear IndexError in ConversableAgent.last_message method (#622)

* Handled possible IndexError in ConversableAgent.last_message method with more clear error message and added test in test_conversable_agent.py.

* Fix code formatting issues.

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Co-authored-by: Chi Wang <wang.chi@microsoft.com>

wonderful committed 2y ago

6bb7acc34df8da9ef845a100859d80040462d743

Parent: fda7a39

Committed by GitHub <noreply@github.com> on 11/11/2023, 6:55:57 PM