input: Write a python function to convert the linked list to a Python list.
  assert linkedlist_to_list(linked_list) == [1, 2, 3, 4] for linked_list containing 1 -> 2 -> 3 -> 4
  assert linkedlist_to_list(linked_list) == [] for an empty linked_list
  assert linkedlist_to_list(linked_list) == [10, 20, 30] for linked_list containing 10 -> 20 -> 30
output: class ListNode:
      def __init__(self, value=0, next=None):
          self.value = value
          self.next = next
  
  def linkedlist_to_list(linked_list):
      result = []
      current = linked_list
      while current:
          result.append(current.value)
          current = current.next
      return result