keras/src/legacy/layers.py/ThresholdedReLU/__init__
class ThresholdedReLU:    def __init__(self, theta=1.0, **kwargs):
        super().__init__(**kwargs)
        if theta is None:
            raise ValueError(
                "Theta of a Thresholded ReLU layer cannot be None, expecting a "
                f"float. Received: {theta}"
            )
        if theta < 0:
            raise ValueError(
                "The theta value of a Thresholded ReLU layer "
                f"should be >=0. Received: {theta}"
            )
        self.supports_masking = True
        self.theta = tf.convert_to_tensor(theta, dtype=self.compute_dtype)