def _input_has_infinite_upper_bound(self) -> bool:
        """Check if any input has infinite upper bound (-1)."""
        for input_spec in self.input_description._fd_spec:
            for size_range in input_spec.type.multiArrayType.shapeRange.sizeRanges:
                if size_range.upperBound == -1:
                    return True
        return False
Check if any input has infinite upper bound (-1).
coremltools/models/model.py