input: 
  from typing import List
  
  def expand_list(list: List) -> None:
      """ Analyze the following Python function to detect any potential errors.
      The function is attempting to modify the list while iterating over it. This 
      can lead to unexpected behavior and should be avoided. To fix the code, the 
      list should be copied before the iteration takes place.
      >>> expand_list([1, 2, 3])
      
      """
      list_copy = list[:]   # make a copy of the list
      for item in list_copy:
          list *= 2
  
output:     list_copy = list[:]   # make a copy of the list
      for item in list_copy:
          list.append(item)