input: Write a function to optimize the given Python code that removes duplicates from an array using built-in functions. Return the array without duplicates.
  
  def removeDuplicates(array): 
      return list(dict.fromkeys(array))
  
  assert removeDuplicates([1, 2, 3, 4, 4, 5]) == [1, 2, 3, 4, 5]
  assert removeDuplicates([10, 10, 2, 3, 5, 5, 7]) == [10, 2, 3, 5, 7]
  assert removeDuplicates([]) == []
  assert removeDuplicates([1, 1, 1, 1]) == [1]
  assert removeDuplicates([1, 2, 3, 4, 5]) == [1, 2, 3, 4, 5]
output: def removeDuplicates(array): 
      return list(dict.fromkeys(array))