class_docstr: A layer that gets fed its answers from an upstream connection,
  for instance from a component earlier in the pipeline.
code: def get_batch_id(cls, inputs: List[Doc]):
      return sum(sum(token.orth for token in doc) for doc in inputs)
  
file_path: spacy-transformers/spacy_transformers/layers/listener.py
imports: from typing import Optional, Callable, List
  from thinc.api import Model
  from spacy.errors import Errors
  from spacy.tokens import Doc
  from ..data_classes import TransformerData
label_desc: Use image node_id 2 for calling the TransformerListener obj's underlying member method code with example usage: obj.get_batch_id(cls, inputs) and returns: sum