input: Write a function to determine if it is possible to create a linked list by performing any number of operations on the given list of nodes. If it is possible return True else return False. If the given list of nodes is empty then return True.
  assert create_linked_list([ListNode(1), ListNode(2), ListNode(3)])==True
  assert create_linked_list([ListNode(1), ListNode(3), ListNode(2)])==True
  assert create_linked_list([ListNode(4), ListNode(3), ListNode(1), ListNode(2)])==False
  assert create_linked_list([ListNode(4), ListNode(3), ListNode(2), ListNode(1)])==False
  assert create_linked_list([])==True
output: def create_linked_list(nodes):
      if not nodes:
          return True
      nodes_set = set(nodes)
      for node in nodes:
          if node.next not in nodes_set:
              return False
      return True