def METHOD_NAME(self):
    """Initiate the parameters either from existing checkpoint or from
    scratch."""
    if isinstance(self.pretrained, str):
        logger = MMLogger.get_current_instance()
        logger.info(f'load model from: {self.pretrained}')
        load_checkpoint(self, self.pretrained, strict=False, logger=logger)
    elif self.pretrained is None:
        for m in self.modules():
            if isinstance(m, nn.Conv3d):
                kaiming_init(m)
            elif isinstance(m, nn.Linear):
                normal_init(m, std=self.init_std)
            elif isinstance(m, _BatchNorm):
                constant_init(m, 1)
    else:
        raise TypeError('pretrained must be a str or None')