under test, not sure no errors

vllm/pooling_params.py

@@ -0,0 +1,23 @@
+from typing import Any, Optional
+
+import msgspec
+
+
+class PoolingParams(
+        msgspec.Struct,
+        omit_defaults=True,  # type: ignore[call-arg]
+        array_like=True):  # type: ignore[call-arg]
+    """Pooling parameters for pooling.
+
+    Attributes:
+        additional_data: Any additional data needed for pooling.
+    """
+    additional_data: Optional[Any] = None
+
+    def clone(self) -> "PoolingParams":
+        """Returns a deep copy of the PoolingParams instance."""
+        return PoolingParams(additional_data=self.additional_data, )
+
+    def __repr__(self) -> str:
+        return (f"PoolingParams("
+                f"additional_metadata={self.additional_data})")