input: Write a function to optimize the given Python code to use built-in functions for removing duplicates from an array. The function should return a list of unique elements in the original order.
  def removeDuplicates(array): 
      return list(dict.fromkeys(array))
      
  assert removeDuplicates([1, 2, 2, 3, 4, 4, 5]) == [1, 2, 3, 4, 5]
  assert removeDuplicates([5, 5, 5, 5]) == [5]
  assert removeDuplicates([]) == []
  assert removeDuplicates([1, 2, 3, 4, 5]) == [1, 2, 3, 4, 5]
  assert removeDuplicates([2, 1, 2, 1, 2]) == [2, 1]
output: def removeDuplicates(array): 
      return list(dict.fromkeys(array))