*   tf.optimizers => tf.keras.optimizers
    *   Add tf.keras.layers.AbstractRNNCell as the preferred implementation of
        RNN cell for TF v2. User can use it to implement RNN cell with custom
        behavior.
    *   Adding `clear_losses` API to be able to clear losses at the end of
        forward pass in a custom training loop in eager.

                                type: string
                              metric:
                                description: |-
                                  One of the well-known [Istio Standard Metrics](https://istio.io/latest/docs/reference/config/metrics/).

                                type: string
                              metric:
                                description: |-
                                  One of the well-known [Istio Standard Metrics](https://istio.io/latest/docs/reference/config/metrics/).