input: Write a function to optimize the given Python code to use built-in functions for removing duplicates from an array. If the given array is empty then return an empty list.
  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([10, 20, 30, 20, 10])==[10, 20, 30]
  assert removeDuplicates([1, 1, 2, 2, 3, 3])==[1, 2, 3]
output: def removeDuplicates(array): 
      return list(dict.fromkeys(array))