input: 
  def generate_string(string_length: int) -> str:
      """ Generate a random string of given length containing alphanumeric characters.
      >>> generate_string(10)
      'aB1cD23eFg'
      >>> generate_string(5)
      '12XyZ'
      """
      random_characters = 'abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789'
      random_string = ''.join(random.choices(random_characters, k=string_length))
      return random_string
  
output:     import random