class_docstr: implements start and end loss of a span e.g. for Question Answering.
docstr: Returns definitions of module input ports.
          
code: def input_types(self):
      """Returns definitions of module input ports."""
      return {
          "logits": NeuralType(("B", "T", "D"), LogitsType()),
          "start_positions": NeuralType(tuple("B"), ChannelType()),
          "end_positions": NeuralType(tuple("B"), ChannelType()),
      }
  
file_path: NeMo/nemo/collections/common/losses/spanning_loss.py
imports: from torch import nn
  from nemo.core.classes import Loss, typecheck
  from nemo.core.neural_types import ChannelType, LogitsType, LossType, NeuralType
label_desc: Use image node_id 1 for calling the SpanningLoss obj's underlying member method code with example usage: obj.input_types() and returns: dict