code: def transform_multiple(sequence, transformations, iterations):
      
      for _ in range(iterations):
          sequence = transform_sequence(sequence, transformations)
      return sequence
docs: Chains a transformation a given number of times.
  
      Args:
          sequence (str): a string or generator onto which transformations are applied
          transformations (dict): a dictionary mapping each char to the string that is
              substituted for it when the rule is applied
          iterations (int): how many times to repeat the transformation
  
      Yields:
          str: the next character in the output sequence.