messages.content: When was the signing of the Treaty of Lisbon?
messages.role: user
messages.role: assistant
messages.arguments: {"event": "Treaty of Lisbon"}
messages.name: get_event_date
messages.type: function
tools: [{"type": "function", "function": {"name": "get_event_date", "description": "Retrieve the date of a historical event.", "parameters": {"type": "dict", "properties": {"event": {"type": "string", "description": "The name of the historical event."}, "location": {"type": "string", "description": "Location where the event took place. Default to global if not specified."}}, "required": ["event"]}}}]