2672..267D    ; valid                  ;      ; NV8    # 3.2  UNIVERSAL RECYCLING SYMBOL..PARTIALLY-RECYCLED PAPER SYMBOL
267E..267F    ; valid                  ;      ; NV8    # 4.1  PERMANENT PAPER SIGN..WHEELCHAIR SYMBOL
2680..2689    ; valid                  ;      ; NV8    # 3.2  DIE FACE-1..BLACK CIRCLE WITH TWO WHITE DOTS

*   Adds `beta` hyperparameter to
    [FTRL](https://www.tensorflow.org/api_docs/python/tf/keras/optimizers/Ftrl)
    optimizer classes (Keras and others) to match
    [FTRL paper](https://research.google.com/pubs/archive/41159.pdf).
*   `Optimizer.__init__` now accepts a `gradient_aggregator` to allow for
    customization of how gradients are aggregated across devices, as well as