keras/src/layers/preprocessing/discretization.py/Discretization/call
class Discretization:    def call(self, inputs):
        indices = self.backend.numpy.digitize(inputs, self.bin_boundaries)
        return numerical_utils.encode_categorical_inputs(
            indices,
            output_mode=self.output_mode,
            depth=len(self.bin_boundaries) + 1,
            dtype=self.compute_dtype,
            sparse=self.sparse,
            backend_module=self.backend,
        )