input: from typing import List
  
  def generate_password(length: int, require_special_char: bool) -> (str or None):
      """ Generates a random password of given length, including alphanumeric characters.
      Optionally, if require_special_char is True, the password must include at least one special character.
  
      >>> generate_password(8, True)
      'A1b2C!d3'  # Example output, actual output will vary due to randomness
      >>> generate_password(10, False)
      '1a2B3c4D5e'  # Example output, actual output will vary due to randomness
      >>> generate_password(5, True)
      None  # Infeasible length for a password with at least one special character
      """
output:     import random
      import string
  
      if length < 1:
          return None
  
      alphanumeric_chars = string.ascii_letters + string.digits
      special_chars = "!@#$%^&*()_+-=[]{}|;':,.<>?/"
  
      if require_special_char and length < 2:
          return None
  
      password = []
      if require_special_char:
          password.append(random.choice(special_chars))
          length -= 1
  
      for _ in range(length):
          password.append(random.choice(alphanumeric_chars))
  
      random.shuffle(password)
      return ''.join(password)