input: def removeDuplicates(array):
      """ Removes duplicates from a given array and returns a new array with unique elements.
      >>> removeDuplicates([1, 2, 2, 3, 4, 4, 5])
      [1, 2, 3, 4, 5]
      >>> removeDuplicates(['a', 'b', 'b', 'c', 'd', 'd'])
      ['a', 'b', 'c', 'd']
      """
output:     seen = set()
      result = []
      for item in array:
          if item not in seen:
              seen.add(item)
              result.append(item)
      return result