from tensorflow.python.framework import ops

      dimensions of `predictions_idx` and `labels`.

  Returns:
    A [D1, ... DN] `Tensor` of false positive counts.
  """
  with ops.name_scope(None, 'false_positives', (predictions_idx, labels)):
    labels, predictions_idx = _maybe_select_class_id(labels,
                                                     predictions_idx,
                                                     class_id)
    fp = set_ops.set_size(set_ops.set_difference(
