input: 
  from typing import List
  
  
  def expand_list(lst: List[any]) -> None:
      """
      The function attempts to modify the list while iterating over it, which can lead to unexpected behavior.
      To avoid this, the list should be copied before the iteration takes place.
      Example:
      >>> lst = [1, 2, 3]
      >>> expand_list(lst)
      >>> lst
      [1, 2, 3, 1, 2, 3]
      """
      list_copy = lst[:]  # make a copy of the list
      for item in list_copy:
          lst *= 2
  
output:     list_copy = lst[:]  # make a copy of the list
      for item in list_copy:
          lst.append(item)