input: Write a function to remove duplicate entries from a list. If the given list is empty, return an empty list.
  
  assert removeDuplicates([1, 2, 2, 3, 3, 4]) == [1, 2, 3, 4]
  assert removeDuplicates([5, 5, 5, 5]) == [5]
  assert removeDuplicates([1, 2, 3, 4, 5]) == [1, 2, 3, 4, 5]
  assert removeDuplicates([]) == []
  assert removeDuplicates([1]) == [1]
output: def removeDuplicates(lst):
      return list(dict.fromkeys(lst))