code: def flatten(nested_list):
      """Flatten a nested list."""
      return [item for a_list in nested_list for item in a_list]
  
file_path: tcav/tcav/utils.py
imports: from scipy.stats import ttest_ind
  import numpy
  import tensorflow
  from tcav.tcav_results.results_pb2 import Result, Results
label_desc: Use image node_id 2 for calling a global function with example usage: flatten(nested_list) and returns: unknown