static adadelta(learningRate = .001, rho = .95, epsilon = null) {
        return new (0, _adadeltaOptimizer.AdadeltaOptimizer)(learningRate, rho, epsilon);
    }
Constructs a `tf.AdadeltaOptimizer` that uses the Adadelta algorithm.
See [https://arxiv.org/abs/1212.5701](https://arxiv.org/abs/1212.5701)

@param learningRate The learning rate to use for the Adadelta gradient
descent algorithm.
@param rho The learning rate decay over each update.
@param epsilon A constant epsilon used to better condition the grad
update.

@doc {heading: 'Training', subheading: 'Optimizers', namespace: 'train'}