required:
                            - name
                            type: object
                          literal:
                            description: Literal adds the same, hard-coded value to
                              each span.
                            properties:
                              value:
                                description: The tag value to use.

                            required:
                            - name
                            type: object
                          literal:
                            description: Literal adds the same, hard-coded value to
                              each span.
                            properties:
                              value:
                                description: The tag value to use.

*   Add `UnifiedGRU` as the new GRU implementation for tf2.0. Change the default
    recurrent activation function for GRU from `hard_sigmoid` to `sigmoid`, and
    `reset_after` to True in 2.0. Historically recurrent activation is
    `hard_sigmoid` since it is fast than 'sigmoid'. With new unified backend
    between CPU and GPU mode, since the CuDNN kernel is using sigmoid, we change