struct TF_VariableInfo {
  TF_VariableInfo() = delete;
  // TF_VariableInfo is constructed here by TensorFlow, and will be passed to
  // plugin as a opaque pointer. Plugin will need to call C APIs below to
  // operate on TF_VariableInfo (such as allocate temp tensor for the `var` held
  // by the underlying tensorflow::VariableInfo.
  TF_VariableInfo(int index, const std::string& name, tensorflow::Var* var) {

//
// On success, place OK in status.
// On failure, place an error status in status.
TF_CAPI_EXPORT extern void TF_RegisterFilesystemPlugin(
    const char* plugin_filename, TF_Status* status);

// Apis that are corresponding to python c api. --------------------

// Add control input to `op`.
TF_CAPI_EXPORT extern void TF_AddOperationControlInput(TF_Graph* graph,