*   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

pkg regexp/syntax, type Regexp struct, Op Op
pkg regexp/syntax, type Regexp struct, Rune []int32
pkg regexp/syntax, type Regexp struct, Rune0 [2]int32
pkg regexp/syntax, type Regexp struct, Sub []*Regexp
pkg regexp/syntax, type Regexp struct, Sub0 [1]*Regexp
pkg runtime, const Compiler ideal-string
pkg runtime, const GOARCH string
pkg runtime, const GOOS string
pkg runtime, func Breakpoint()
pkg runtime, func CPUProfile() []uint8