    def add_args(parser):
        """Add task-specific arguments to the parser."""
        # fmt: off
        MultilingualTranslationTask.add_args(parser)
        parser.add_argument('--lambda-parallel-config', default="1.0", type=str, metavar='CONFIG',
                            help='cross-entropy reconstruction coefficient (parallel data). '
                                 'use fixed weight during training if set to floating point number. '
                                 'use piecewise linear function over number of updates to schedule the '
                                 'weight with the format: w0:step0,w1:step1,...')
        parser.add_argument('--lambda-denoising-config', default="0.0", type=str, metavar='CONFIG',
                            help='Cross-entropy reconstruction coefficient (denoising autoencoding)'
                                 'use fixed weight during training if set to floating point number. '
                                 'use piecewise linear function over number of updates to schedule the '
                                 'weight with the format: w0:step0,w1:step1,...')
        parser.add_argument('--lambda-otf-bt-config', default="0.0", type=str, metavar='CONFIG',
                            help='cross-entropy reconstruction coefficient (on-the-fly back-translation parallel data)'
                                 'use fixed weight during training if set to floating point number. '
                                 'use piecewise linear function over number of updates to schedule the '
                                 'weight with the format: w0:step0,w1:step1,...')
        parser.add_argument('--bt-max-len-a', default=1.1, type=float, metavar='N',
                            help='generate back-translated sequences of maximum length ax + b, where x is the '
                                 'source length')
        parser.add_argument('--bt-max-len-b', default=10.0, type=float, metavar='N',
                            help='generate back-translated sequences of maximum length ax + b, where x is the '
                                 'source length')
        parser.add_argument('--bt-beam-size', default=1, type=int, metavar='N',
                            help='beam size used in beam search of online back-translation')
        parser.add_argument('--max-word-shuffle-distance', default=3.0, type=float, metavar='N',
                            help='maximum word shuffle distance for denoising autoencoding data generation')
        parser.add_argument('--word-dropout-prob', default=0.1, type=float, metavar='N',
                            help='word dropout probability for denoising autoencoding data generation')
        parser.add_argument('--word-blanking-prob', default=0.2, type=float, metavar='N',
                            help='word blanking probability for denoising autoencoding data generation')
Add task-specific arguments to the parser.
fairseq/tasks/semisupervised_translation.py