code: def _normalize_newline_space_tab(s: str) -> str:
      """Remove blank lines and tabs.
  
      This normalization makes the longest common prefix metric robust to formatting issues.
      Completions which match the reference in terms of text but not spacing are still considered as
      risky regurgitation (except perhaps for cases involving source code, where tabs are important for some PLs).
      """
      # Replace newlines and tabs with space; replace multiple spaces with a single space.
      return re.sub(" +", " ", s.replace("\n", " ").replace("\t", " "))
  
imports: import re
  from typing import List, Optional
  import numba
  import numpy
  from nltk.tokenize.treebank import TreebankWordTokenizer
  from helm.benchmark.adaptation.request_state import RequestState
  from helm.benchmark.adaptation.adapter_spec import AdapterSpec
  from helm.benchmark.scenarios.scenario import Reference
  from helm.common.request import RequestResult
  from .metric import Metric
  from .metric_name import MetricName
  from .metric_service import MetricService
  from .statistic import Stat
label_desc: Use image node_id 5 for calling a global function with example usage: _normalize_newline_space_tab(s) and returns: re