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