input: 
  def removeDuplicates(arr):
      """This function takes an array of strings and removes all duplicates, returning the resulting array.
      
      >>> removeDuplicates(['a', 'b', 'a', 'c', 'c', 'd'])
      ['a', 'b', 'c', 'd']
      >>> removeDuplicates(['x', 'y', 'x', 'y', 'z'])
      ['x', 'y', 'z']
      """
      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
  
output:     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