text: """Test 2.1."""
  
  import sys
  sys.path.insert(0, '/Users/zt/programming/interviews/interview-prep/cracking-the-coding-interview/data_structures')
  from linked_list import LinkedList
  
  
  def test_removes_val():
      """Test that the remove dup function removes duplicates."""
      from CTCI_2_1 import remove_dups
      ll = LinkedList()
      ll.push(1)
      ll.push(2)
      ll.push(3)
      ll.push(3)
      ll.push(4)
      ll.push(5)
      ll.push(6)
      remove_dups(ll)
      assert ll.as_list() == [6, 5, 4, 3, 2, 1]
  