input: Write a function to remove all the duplicates from a linked list in Python.
  
  class Node: 
      def __init__(self, data): 
          self.data = data 
          self.next = None 
    
  class LinkedList: 
      def __init__(self): 
          self.head = None
  
      def remove_duplicates(self, list_nodes):
          curr_node= self.head 
          new_list=[]
          while curr_node != None: 
              if curr_node.data not in new_list: 
                  new_list.append(curr_node.data) 
              curr_node = curr_node.next
                  
          self.head=None
          for i in new_list:
              self.insert_node(i)
      
      def insert_node(self, data): 
          new_node = Node(data) 
          if self.head is None: 
              self.head = new_node 
              return
          last = self.head 
          while (last.next): 
              last = last.next
          last.next =  new_node
  
  assert remove_duplicates([7, 14, 28, 28, 28, 35, 49])==[7, 14, 28, 35, 49]
  assert remove_duplicates([5, 5, 5, 5])==[5]
  assert remove_duplicates([])==[]
  assert remove_duplicates([1, 2, 3, 4, 5])==[1, 2, 3, 4, 5]
output: def remove_duplicates(self, list_nodes):
      curr_node = self.head 
      new_list = []
      while curr_node != None: 
          if curr_node.data not in new_list: 
              new_list.append(curr_node.data) 
          curr_node = curr_node.next
              
      self.head = None
      for i in new_list:
          self.insert_node(i)