chore: import upstream snapshot with attribution

tests/realtime/test_model_events.py

@@ -0,0 +1,51 @@
+from typing import get_args
+
+import agents.realtime as realtime
+from agents.realtime.model_events import RealtimeModelEvent
+from agents.usage import Usage
+
+
+def test_all_events_have_type() -> None:
+    """Test that all events have a type."""
+    events = get_args(RealtimeModelEvent)
+    assert len(events) > 0
+    for event in events:
+        assert event.type is not None
+        assert isinstance(event.type, str)
+
+
+def test_usage_event_types_are_publicly_exported() -> None:
+    expected_exports = {
+        "RealtimeModelCachedTokensDetails",
+        "RealtimeModelInputTokensDetails",
+        "RealtimeModelOutputTokensDetails",
+        "RealtimeModelUsageEvent",
+    }
+
+    assert expected_exports <= set(realtime.__all__)
+    for name in expected_exports:
+        assert getattr(realtime, name) is not None
+
+
+def test_custom_model_can_construct_typed_usage_without_openai_types() -> None:
+    event = realtime.RealtimeModelUsageEvent(
+        usage=Usage(requests=1, input_tokens=8, output_tokens=5, total_tokens=13),
+        input_tokens_details=realtime.RealtimeModelInputTokensDetails(
+            text_tokens=2,
+            audio_tokens=6,
+            cached_tokens=3,
+            cached_tokens_details=realtime.RealtimeModelCachedTokensDetails(
+                text_tokens=1,
+                audio_tokens=2,
+            ),
+        ),
+        output_tokens_details=realtime.RealtimeModelOutputTokensDetails(
+            text_tokens=1,
+            audio_tokens=4,
+        ),
+    )
+
+    assert event.input_tokens_details is not None
+    assert event.input_tokens_details.audio_tokens == 6
+    assert event.output_tokens_details is not None
+    assert event.output_tokens_details.audio_tokens == 4