Allow Groot fake RTC chunk prefetch

tests/policies/groot/test_groot_n1_7.py

@@ -14,6 +14,7 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
+import inspect
 import json
 import sys
 from types import SimpleNamespace
@@ -419,6 +420,13 @@ def test_groot_n1_7_can_be_selected_from_policy_config_factory_without_external_
     assert "gr00t" not in sys.modules
 
 
+def test_groot_predict_action_chunk_accepts_rtc_kwargs():
+    signature = inspect.signature(GrootPolicy.predict_action_chunk)
+
+    assert any(parameter.kind is inspect.Parameter.VAR_KEYWORD for parameter in signature.parameters.values())
+    signature.bind(object(), {}, inference_delay=2, prev_chunk_left_over=None)
+
+
 def test_groot_from_pretrained_rejects_mismatched_caller_config(tmp_path):
     model_path = tmp_path / "GR00T-N1.7-local"
     model_path.mkdir()