TF_Graph* parent = params->cond_graph->parent;
  TF_Output* parent_inputs = params->cond_graph->parent_inputs;
  int num_loop_vars = params->ninputs;

  mutex_lock l(parent->mu);

  // 'cond_fn' copies the cond graph into the parent graph.
  tensorflow::ops::CondGraphBuilderFn cond_fn =
      [params, parent](const tensorflow::Scope& scope,

namespace tensorflow {
namespace gradients {
TapeOperation::TapeOperation(AbstractOperation* parent_op, Tape* tape,
                             const GradientRegistry& registry)
    : AbstractOperation(kTape),
      parent_op_(parent_op),
      tape_(tape),
      registry_(registry) {
  // TODO(b/172003047): Consider making AbstractOperation RefCounted.
  // parent_op_->Ref();
}
void TapeOperation::Release() {
  // TODO(srbs): Change to Unref().

}

TEST_P(ModularFileSystemTest, TestDeleteRecursivelyANestedDir) {
  const std::string parent_path = GetURIForPath("parent/path");
  Status status = env_->RecursivelyCreateDir(parent_path);
  if (!status.ok())
    GTEST_SKIP() << "RecursivelyCreateDir() not supported: " << status;

  const std::string new_dirpath = GetURIForPath("parent/path/that/is/extended");
  status = env_->RecursivelyCreateDir(new_dirpath);
  if (!status.ok())

    : AbstractContext(kTape), parent_ctx_(c), tape_(tape), registry_(registry) {
  // TODO(srbs): Make AbstractContext ref counted.
  // parent_ctx_->Ref();
}
void TapeContext::Release() {
  // TODO(srbs): Change to Unref()
  delete this;
}
TapeContext::~TapeContext() {
  // TODO(srbs): Make AbstractContext ref counted.
  // parent_ctx_->Unref();
}
TapeOperation* TapeContext::CreateOperation() {