keras/src/metrics/iou_metrics.py/BinaryIoU/__init__
class BinaryIoU:    def __init__(
        self,
        target_class_ids=(0, 1),
        threshold=0.5,
        name=None,
        dtype=None,
    ):
        super().__init__(
            num_classes=2,
            target_class_ids=target_class_ids,
            name=name,
            dtype=dtype,
        )
        self.threshold = threshold