text: from random import randint
  from insertion import random_number_insertion
  
  
  def random_index(a_list):
      return randint(0, len(a_list) - 1)
  
  
  def random_increase(a_list):
      '''Increases a random number in a list, O(1)'''
      index = random_index(a_list)  # Assuming randint and len runs in O(1)
      a_list[index] += 1  # O(1)
  
  if __name__ == "__main__": 
      # Tests for accuracy
      for _ in range(200):
          my_list = random_number_insertion(10)
          prelim_sum = sum(my_list)
          random_increase(my_list)
          assert sum(my_list) == prelim_sum + 1
  
      my_list = random_number_insertion(10)
      prelim_sum = sum(my_list)
      for _ in range(200):
          random_increase(my_list)
          assert sum(my_list) == prelim_sum + 1
          prelim_sum += 1
  