    def add_args(parser):
        """Add optimizer-specific arguments to the parser."""
        # fmt: off
        parser.add_argument('--adadelta-rho', type=float, default=0.9, metavar='RHO',
                            help='coefficient used for computing a running average of squared gradients')
        parser.add_argument('--adadelta-eps', type=float, default=1e-6, metavar='EPS',
                            help='term added to the denominator to improve numerical stability')
        parser.add_argument('--weight-decay', '--wd', default=0.0, type=float, metavar='WD',
                            help='weight decay')
        parser.add_argument('--anneal-eps', action='store_true', help='flag to anneal eps')
Add optimizer-specific arguments to the parser.
fairseq/optim/adadelta.py