input: Write a class that represents a linked list node in Python. The class should have an initializer method that takes data as an argument and initializes the node with that data and sets the next pointer to None.
  
  class ListNode:
      def __init__(self, data):
          self.data = data
          self.next = None
output: class ListNode:
      def __init__(self, data):
          self.data = data
          self.next = None