[](void* data, size_t, void* arg) {
              delete reinterpret_cast<DataType*>(data);
            },
            nullptr),
        TF_DeleteTensor);
    // TODO(allenl): Here and when executing regular operations, we could hold
    // on to one TFE_Op per device and just call TFE_ResetOp to avoid parsing
    // device names repeatedly.
    std::unique_ptr<TFE_Op, decltype(&TFE_DeleteOp)> const_op(

//                 must either have the same length as `outputs`
//                 (i.e. `noutputs`) or be null. In the former case,
//                 the names should match the regular expression for ArgDef
//                 names - "[a-z][a-z0-9_]*". In the latter case,
//                 names for outputs will be generated automatically.