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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def encipher_shift(plaintext, plain_vocab, shift):
 """Encrypt plain text with a single shift layer. Args: plaintext (list of list of Strings):
 a list of plain text to encrypt. plain_vocab (list of Integer):
 unique vocabularies being used. shift (Integer):
 number of shift, shift to the right if shift is positive. Returns: ciphertext (list of Strings):
 encrypted plain text. """

  ciphertext = []
  cipher = ShiftEncryptionLayer(plain_vocab, shift)

  for _, sentence in enumerate(plaintext):
    cipher_sentence = []
    for _, character in enumerate(sentence):
      encrypted_char = cipher.encrypt_character(character)
      cipher_sentence.append(encrypted_char)
    ciphertext.append(cipher_sentence)

  return ciphertext