class_docstr: Inverse square root LR scheduler.
  
  Args:
      optimizer (Optimizer): Torch optimizer.
      warmup_steps (int): Number of warmup steps.
      warmup_init_lr (tp.Optional[float]): Initial learning rate
          during warmup phase. When not set, use the provided learning rate.
code: def get_lr(self):
      return [
          self._get_sched_lr(base_lr, self.last_epoch)
          for base_lr in self.base_lrs
      ]
  
file_path: audiocraft/audiocraft/optim/linear_warmup_lr_scheduler.py
imports: import typing
  from torch.optim import Optimizer
  from torch.optim.lr_scheduler import _LRScheduler
label_desc: Use image node_id 3 for calling the LinearWarmupLRScheduler obj's underlying member method code with example usage: obj.get_lr() and returns: unknown