message: Minor fix for lt.map_fn, handling a case where Tensor type inference can fail.
diff: @@ -652,7 +652,8 @@ def map_fn(fn, labeled_tensor, name=None):
  tensor_lt = core.LabeledTensor(tensor, original_axes)
  return fn(tensor_lt).tensor
  - map_op = functional_ops.map_fn(tf_fn, labeled_tensor.tensor)
  + map_op = functional_ops.map_fn(
  + tf_fn, labeled_tensor.tensor, dtype=first_map_lt.dtype)
  map_lt = core.LabeledTensor(map_op, final_axes)
  return core.identity(map_lt, name=scope)
  