class_docstr: Vinegre cipher.
class_docstr_tok: ["Vinegre","cipher","."]
code: def generator(self, nbr_symbols, max_length, nbr_cases):
      plain_vocab = range(nbr_symbols)
      indices = generate_plaintext_random(
          plain_vocab, self.distribution, nbr_cases, max_length
      )
      codes = encipher_vigenere(indices, plain_vocab, self.key)
      for plain, code in zip(indices, codes):
          yield {"inputs": plain, "targets": code}
  
imports: from __future__ import absolute_import
  from __future__ import division
  from __future__ import print_function
  from collections import deque
  import numpy
  from tensor2tensor.data_generators import algorithmic
  from tensor2tensor.utils import registry
label_desc: Use image node_id 4 for calling the AlgorithmicCipherVigenere5 obj's underlying member method code with example usage: obj.generator(nbr_symbols, max_length, nbr_cases) without return types