class_docstr: Base class to calculate the loss during training.
  
  This implementation of :class:`torch.nn.Module` allows building
  the loss object from a configuration file.
docstr: Instantiates a ClassyLoss from a configuration.
  
  Args:
      config: A configuration for a ClassyLoss.
  
  Returns:
      A ClassyLoss instance.
code: def from_config(cls, config: Dict[str, Any]) -> "ClassyLoss":
      """Instantiates a ClassyLoss from a configuration.
  
      Args:
          config: A configuration for a ClassyLoss.
  
      Returns:
          A ClassyLoss instance.
      """
      raise NotImplementedError()
  
file_path: ClassyVision/classy_vision/losses/classy_loss.py
imports: from typing import Any, Dict
  import torch.nn
label_desc: Use image node_id 2 for calling the ClassyLoss obj's underlying member method code with example usage: obj.from_config(cls, config) without return types