input: 
  def removeDuplicates(array):
      """Optimize the given code to use built-in functions. 
      This function removes duplicates from a list and returns a new list without duplicates.
      >>> removeDuplicates([1, 2, 2, 3, 4, 5, 6, 6])
      [1, 2, 3, 4, 5, 6]
      >>> removeDuplicates(['a', 'b', 'a', 'c'])
      ['a', 'b', 'c']
      """
  
output:     return list(dict.fromkeys(array))