class_docstr: Decay the LR based on the inverse square root of the update number.
  
  Example:
  
      .. code-block:: python
  
          start_value: 4.8
          warmup_interval_length: 0.1
  Corresponds to a inverse sqrt decay schedule with values in [4.8, 0]
code: def __init__(
      self,
      start_value: float,
      warmup_interval_length: float,
      update_interval: UpdateInterval = UpdateInterval.STEP,
  ):
      super().__init__(update_interval=update_interval)
      self._start_value = start_value
      self.warmup_interval_length = warmup_interval_length
  
      self.decay_factor = self._start_value
      if self.warmup_interval_length > 0.0:
          self.decay_factor = (
              self._start_value * self.warmup_interval_length**0.5
          )
  
imports: from typing import Any, Dict
  from classy_vision.optim.param_scheduler import ClassyParamScheduler, register_param_scheduler, UpdateInterval
label_desc: Use image node_id 1 to create a new InverseSqrtScheduler object from inherited base classes: ClassyParamScheduler with example: obj = InverseSqrtScheduler(start_value, warmup_interval_length, update_interval)