code: def build_nonlinearity(nonlinearity):
      """
      Look up "nonlinearity" in a map from function name to function, build the appropriate layer.
      """
      if nonlinearity in NONLINEARITY:
          return NONLINEARITY[nonlinearity]()
      raise ValueError(
          'Chosen value of nonlinearity, "%s", not handled'
          % nonlinearity
      )
  
file_path: stanza/stanza/models/constituency/utils.py
imports: from collections import Counter, deque
  import copy
  import logging
  import torch.nn
  from torch import optim
  from stanza.models.common.doc import TEXT, Document
  from stanza.utils.get_tqdm import get_tqdm
label_desc: Use image node_id 4 for calling a global function with example usage: build_nonlinearity(nonlinearity) and returns: NONLINEARITY