input: def removeDuplicates(arr):
      result = []
  
      # traverse for all elements 
      for i in arr:
  
          # check if exists in result 
          if i not in result:
              result.append(i)
  
      # return result 
      return result
  
  """
  >>> removeDuplicates(['a', 'b', 'a', 'c', 'c', 'd'])
  ['a', 'b', 'c', 'd']
  >>> removeDuplicates(['x', 'y', 'x', 'z', 'y'])
  ['x', 'y', 'z']
  """
output:     return result