message: Fix flaky test by re-introducing a dependency that may be short-cut via static shape inference.
diff: @@ -1652,6 +1652,7 @@ def _move_sparse_tensor_out_context(input_context, input_sequences, num_unroll):
  if input_sequences:
  seq = list(input_sequences.values())[0]
  if isinstance(seq, ops.Tensor):
  + with ops.control_dependencies([seq]):
  value_length = array_ops.shape(seq)[0]
  else:
  value_length = seq.dense_shape[0]
  