input: Write a function to optimize the given Python code that removes duplicates from a given array using built-in functions. If the array is empty, return an empty array.
  def removeDuplicates(array): 
      return list(dict.fromkeys(array))
  
  assert removeDuplicates([1, 2, 2, 3, 4, 4])==[1, 2, 3, 4]
  assert removeDuplicates([5, 5, 5, 5, 5])==[5]
  assert removeDuplicates([10, 20, 30, 20, 10])==[10, 20, 30]
  assert removeDuplicates([])==[]
  assert removeDuplicates([1])==[1]
output: def removeDuplicates(array): 
      return list(dict.fromkeys(array))