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
  
  # Example test cases:
  # >>> removeDuplicates(['a', 'b', 'a', 'c', 'c', 'd'])
  # ['a', 'b', 'c', 'd']
  # >>> removeDuplicates(['z', 'y', 'z', 'x', 'y'])
  # ['z', 'y', 'x']
  
output:     return result