code: def _get_backoff_prob(n: int, alpha: float) -> float:
      """Computes the back-off probability given current count and alpha value."""
      return (n + 1) ** -alpha
  
file_path: datasets/tensorflow_datasets/text/c4_wsrs/c4_wsrs_utils.py
imports: from __future__ import annotations
  import collections
  import dataclasses
  import random
  import re
  from typing import Iterator, Mapping, Sequence, Tuple
  import numpy
label_desc: Use image node_id 1 for calling a global function with example usage: _get_backoff_prob(n, alpha) and returns: unknown