Function case_v2

Create a case operation. See also `tf.switch_case`. The `pred_fn_pairs` parameter is a list of pairs of size N. Each pair contains a boolean scalar tensor and a python callable that creates the tensors to be returned if the boolean evaluates to True. `default` is a callable generating a

(pred_fn_pairs,
            default=None,
            exclusive=False,
            strict=False,
            name="case")