code: def logsumexp2(arr):
      max_ = arr.max()
      return np.log2(np.sum(2 ** (arr - max_))) + max_
  
imports: import itertools
  import re
  from nltk.metrics import accuracy
  from nltk.probability import ConditionalFreqDist, ConditionalProbDist, DictionaryConditionalProbDist, DictionaryProbDist, FreqDist, LidstoneProbDist, MLEProbDist, MutableProbDist, RandomProbDist
  from nltk.tag.api import TaggerI
  from nltk.util import LazyMap, unique_list
label_desc: Use image node_id 3 for calling a global function with example usage: logsumexp2(arr) and returns: unknown